How Trades Work: A Beginner’s Guide

By now, you understand what trading is, how financial markets function, and what types of markets and instruments exist. This naturally raises a more practical question: what actually happens when you click “buy” or “sell”?

This guide walks through the mechanics of a trade from start to finish. You’ll learn what it means to open and close a position, how orders get executed, why prices are quoted as two numbers instead of one, and how profit or loss is actually calculated. You’ll also be introduced to concepts like liquidity, slippage, margin, and leverage — not as advanced trading topics, but as basic mechanics every trader eventually needs to understand.

This article does not teach trading strategy. It explains how a trade works so that later guides on order types, chart reading, and analysis will make sense in context.

What Happens When You Place a Trade?

Before looking at each concept individually, it helps to see the general sequence a trade follows.

A trader first decides to buy or sell a particular asset. That decision becomes an order which is an instruction describing what to trade, how much, and under what conditions. The order is then sent to a broker, which routes it to the relevant trading venue, such as an exchange, a market maker, or another execution system, depending on the asset being traded.

Once the order is executed, the trader holds an open position. From that point, the position’s value moves along with the market price, producing an unrealized gain or loss. When the trader eventually closes the position, that unrealized result becomes realized profit or loss, adjusted for any applicable trading costs.

The remainder of this guide explains each part of that sequence in more detail. The specific ways a trader can structure an order, for example choosing to execute immediately or only at a certain price, are covered in the next guide “Order Types Explained”.

What Does Buying and Selling Mean in Trading?

Buying and selling sound simple, but in trading they carry a specific meaning that’s worth clarifying.

Buying generally means acquiring a position in an asset. In most everyday cases, this means opening a long position which benefits if the price rises.

Selling can mean two different things, and this is where confusion often starts. Selling can mean closing a long position you already hold, effectively exiting the trade. It can also mean opening a short position, where a trader sells an asset first, expecting to buy it back later at a lower price.

Because “sell” can refer to either action depending on context, it’s worth paying attention to whether a trade is being opened or closed, not just whether it’s a buy or a sell.

What Are Long and Short Positions?

A long position is a position that increases in value when the price of the asset rises. Going long is the more familiar direction for most beginners: buy low, and hope to sell higher later.

A short position is a position that increases in value when the price of the asset falls. Traditional short selling generally involves borrowing the asset, selling it at the current price, and later buying it back to return what was borrowed. If the price has fallen in the meantime, the difference is the trader’s profit. If the price has risen instead, the trader takes a loss.

The exact mechanics of short selling vary by market. In some markets, such as certain derivatives, going short doesn’t require borrowing anything, and the trader simply agrees to a contract that gains value when price falls. Rather than treating short selling as identical across every market, it’s more accurate to understand the underlying idea: a short position is a bet that price will fall, achieved through mechanics that differ depending on the instrument.

What Does It Mean to Open and Close a Trade?

Opening a trade means entering a position, either long or short, that didn’t exist before. Closing a trade means exiting that position, which removes the trader’s exposure to further price movement in that asset.

It’s worth being precise here, because these terms are sometimes confused with unrelated concepts that use similar language:

• Opening and closing a position refers to entering and exiting a trade.
• The opening price and closing price of a candlestick refer to the first and last price recorded during a specific time period on a chart which is a completely different concept and covered in later guides.
• The opening and closing of a market refers to trading hours, such as when an exchange begins or ends its trading session for the day.

These three ideas all use the words “open” and “close,” but they describe unrelated things. Keeping them separate makes later concepts, like reading a chart, much easier to follow.

How Does a Trade Get Executed?

When a trader submits an order, the order doesn’t simply match with another individual trader directly. It’s routed through a broker to the relevant trading venue for that market.

Depending on the asset, this might mean:

• An order book on a centralized exchange, where buy and sell orders are matched based on price and time.
• A market maker or liquidity provider, who quotes prices and takes the other side of trades in over-the-counter markets.
• An electronic network that connects multiple participants and venues.

The exact path an order takes depends on the market and the broker involved. What matters at this stage is understanding that execution is a process, not an instant handshake between two people. That process is what turns a submitted order into an open position.

Traders can also choose different types of orders to control how and when execution happens. For example, instructing a broker to execute immediately at the current price, or only if the price reaches a specific level. Those instructions are covered in detail in the next guide “Order Types Explained”.

What Are Bid, Ask, and the Bid-Ask Spread?

Every tradable asset has two prices at any given moment, not one. The bid price is the highest price a buyer is currently willing to pay. The ask price (sometimes called the offer) is the lowest price a seller is currently willing to accept.

For example, an asset might show a bid of $100.00 and an ask of $100.05. A trader who wants to buy immediately generally pays the ask price, while a trader who wants to sell immediately generally receives the bid price.

The difference between the two (in this case, $0.05) is called the bid-ask spread. The spread exists because buyers and sellers rarely agree on an identical price, and it represents a cost built into entering and exiting a trade: a trader who buys at the ask and immediately sells at the bid would show a small loss equal to the spread, even if the market hasn’t moved at all.

Spreads tend to be narrower for assets with high liquidity and wider for assets that are traded less frequently, which is discussed further in the next section.

This concept is unrelated to “spread trading,” a different term used to describe certain strategies involving multiple positions at once.

What Is Market Liquidity?

Liquidity refers to how easily an asset can be bought or sold without causing a significant change in its price.

A highly liquid asset typically has many buyers and sellers active at any given time. Orders can usually be filled quickly, spreads tend to be narrower, and large orders are less likely to move the price significantly.

A less liquid asset has fewer active participants. Orders may take longer to fill, spreads tend to be wider, and even moderately sized orders can shift the price more noticeably.

Liquidity isn’t fixed, and it can change based on the time of day, overall market conditions, or how actively a particular asset is being traded. Understanding liquidity helps explain why the same trade might execute smoothly in one asset or market condition and less smoothly in another, which connects directly to the next concept: slippage.

What Is Slippage in Trading?

Slippage occurs when the price at which a trade is actually executed differs from the price the trader expected when submitting the order.

Slippage tends to happen more often under certain conditions:

• When prices are moving rapidly.
• When liquidity is low relative to the size of the order.
• When an order is unusually large.
• When a significant gap or sudden market event occurs.

It’s worth noting that slippage isn’t inherently bad. A trade can execute at a better price than expected, just as it can execute at a worse one. What matters is understanding that the price seen before submitting an order is not always guaranteed to be the price received.

How Is Profit or Loss Calculated?

Profit or loss in a trade generally comes down to the difference between the entry price and the exit price, adjusted for position size and any applicable trading costs.

For a long position: If a trader buys 10 units of an asset at $50 and later sells them at $55, the result is a gain of $5 per unit, or $50 total, before costs.

For a short position: If a trader sells 10 units short at $55 and later buys them back at $50, the result is also a gain of $5 per unit, or $50 total before costs, because the position benefits when price falls.

While a position remains open, any gain or loss is unrealized, sometimes called floating profit or loss. It reflects what the position would be worth if closed at that moment, but it isn’t final and can change as the price continues to move.

Once a position is closed, that result becomes realized profit or loss. At this point, the outcome is locked in and is no longer affected by future price movement in that trade, although it can still be affected by trading costs, discussed next.

What Are Trading Costs?

Several types of costs can affect the final result of a trade, beyond the raw price difference between entry and exit.

• The bid-ask spread, discussed earlier, is effectively a cost built into entering and exiting a position.
• Commissions are fees some brokers charge per trade or per unit traded.
• Financing or overnight costs can apply to positions held open for extended periods, particularly when leverage is involved.
• Other fees, such as account or platform fees, may apply depending on the broker and market.

Not every market or broker charges every type of cost, and the specific amounts vary widely. The important takeaway is that the price difference between entry and exit is rarely the complete picture, and trading costs should be factored into the final result.

What Are Margin and Leverage in Trading?

Margin and leverage are closely related concepts that allow a trader to control a larger position than their own capital would otherwise allow. Their exact mechanics differ depending on the market, so it’s worth understanding the general idea before assuming it works identically everywhere.

In a securities margin account, margin generally involves borrowing money from a broker, using the trader’s holdings as collateral, to purchase a larger position than the trader’s own funds would cover.

In futures markets, margin generally functions differently, and it’s more like a performance bond that demonstrates a trader can cover potential losses, rather than a down payment on the underlying asset.

Other markets and products, including many forex and cryptocurrency trading platforms, use their own margin and collateral arrangements, which can differ from both of the examples above.

Leverage describes the ratio between the size of a position and the capital required to open it. For example, if a broker allows 10:1 leverage, a trader might control a $10,000 position using $1,000 of their own capital.

Leverage is often described as a way to amplify potential gains, but it’s equally accurate and arguably more important to understand that leverage amplifies potential losses in the same way. A price movement that would produce a modest loss without leverage can produce a much larger loss with it, sometimes exceeding the capital originally committed to the trade.

Because the mechanics of margin and leverage vary meaningfully by market, broker, account type, and jurisdiction, it’s worth reviewing the specific terms of any account before assuming a particular figure or structure applies.

What Is a Margin Call?

A margin call occurs when a trader’s account no longer holds enough funds to support the positions they have open, typically because losses have reduced the account’s value below a required threshold.

When this happens, a broker may require the trader to deposit additional funds, or it may close some or all open positions to bring the account back within acceptable limits.

Margin calls exist because leveraged positions can lose more than the funds initially committed to them, and so they occur when account equity or available margin falls below required levels. At this stage of learning, understanding that this risk exists is more important than memorizing the specific thresholds used by any particular broker, since these vary considerably.

Common Misconceptions About How Trades Work

Before putting these concepts together, it’s worth correcting a few misunderstandings that commonly trip up beginners.

“Selling” always means going short. As explained earlier, selling can mean closing an existing long position or opening a new short position. The two are different actions with different implications.

The price shown before an order is submitted is guaranteed. Because of slippage, the executed price can differ from the price a trader saw moments earlier, particularly during fast-moving or illiquid conditions.

Leverage makes a trade more likely to succeed. Leverage changes the size of a position relative to the trader’s capital. It doesn’t improve the odds of a favorable price movement. It simply magnifies the financial impact of whatever happens, either win or loss.

A losing trade means a mistake was made. A trade can be based on sound reasoning and still result in a loss, because markets involve uncertainty. Evaluating decisions by their process, rather than solely by their outcome, is a theme worth keeping in mind as you continue learning.

A Complete Example: From Opening a Trade to Closing It

Here’s how these concepts fit together in a single, simplified example.

A trader is watching an asset quoted at a bid of $100.00 and an ask of $100.10. The trader decides to buy, submits an order, and it’s executed at the ask price of $100.10, opening a long position of 10 units.

Over the next few hours, the price rises. At one point, the position is worth $101.50 per unit, showing an unrealized gain of $1.40 per unit, or $14.00 total. This gain is not final — it reflects the position’s value at that moment and would change if the price moved again.

The trader then decides to close the position. The order is submitted and executed at a bid price of $102.00. The realized result is the difference between the entry price ($100.10) and the exit price ($102.00), or $1.90 per unit, which is a total of $19.00 before costs. If the broker charges a commission or other fees, those would be subtracted from this amount to determine the final result.

A brief short example: Suppose instead the trader expected the price to fall. They open a short position at a bid of $100.00, and the price later falls to an ask of $98.50. Closing the short position means buying back at $98.50, producing a realized gain of $1.50 per unit, because a short position benefits when price falls.

In both cases, the same underlying sequence applies: a decision leads to an order, the order is executed at a specific price, the position produces an unrealized result that changes with the market, and closing the position converts that result into a realized outcome, adjusted for costs.

How Do Traders Make Money?

In general terms, traders attempt to make money by opening positions that benefit from the price movements or other outcomes they anticipate, and by managing those positions in a way that limits losses when their expectations don’t play out.

It’s worth being direct about an important distinction: understanding how a trade works (orders, execution, positions, P&L, margin) is not the same as knowing how to trade profitably. Profitability generally depends on factors this guide hasn’t covered yet, including analysis, strategy, and risk management, which are addressed in later guides within the Library.

There’s no reliable shortcut to consistent profitability, and no indicator, strategy, or piece of knowledge guarantees it. This guide’s goal is to make sure the mechanics of a trade are clear before moving on to how traders analyze markets and make decisions.

How Much Money Do You Need to Start Trading?

There’s no single answer to this question, because it depends on several factors:

• The market and instrument being traded.
• The broker’s minimum deposit requirements.
• The account type offered.
• Regulatory requirements in the trader’s jurisdiction.
• Margin requirements and available leverage, where applicable.

It’s also worth separating two different questions. One is the minimum amount a broker technically allows someone to deposit, which in some cases can be quite small. The other is the amount of capital that might be appropriate for someone to trade responsibly, which depends on personal financial circumstances that this guide has no way of knowing.

TradeConverge doesn’t provide personalized financial advice, and readers should evaluate their own situation, or consult a qualified professional, before committing capital to trading.

Frequently Asked Questions

What does P&L mean in trading? P&L stands for profit and loss. It refers to the financial result of a trade, which can be unrealized while a position is open or realized once it’s closed.

Is slippage always bad for traders? No. Slippage simply means the executed price is different from the expected price. It can result in a better price or a worse one, depending on how the market moves at the moment of execution.

What’s the difference between the bid-ask spread and “spread trading”? The bid-ask spread is the gap between the buy and sell prices quoted for an asset. Spread trading is a different concept involving strategies built around multiple positions, and it isn’t covered in this guide.

Do all markets use leverage the same way? No. Leverage and margin requirements vary significantly across securities, futures, forex, and cryptocurrency markets, as well as between individual brokers and account types.

Can a position lose more money than was originally invested? In some leveraged markets and instruments, yes — losses can exceed the capital initially committed, which is part of why margin calls exist. This varies by market and account type.

Do I need to understand order types before I start trading? Yes, it helps. This guide introduced the general idea of submitting and executing an order, but the different ways a trader can structure an order, and when each type of order might be used, are covered in the next guide where order types are explained.

The Bottom Line

A trade is more than a single click. It’s a sequence: a decision becomes an order, the order is executed through a broker or trading venue, a position opens, its value moves with the market, and closing it converts an unrealized result into a realized one, and this process is shaped along the way by spreads, liquidity, slippage, and trading costs.

With this foundation in place, you’re ready to look more closely at the different ways a trader can instruct a broker to execute a trade, which is the subject of the next guide.