How Financial Markets Work

Concept

A financial market is not a single place or a magic number on a screen. It is what happens when people who want to buy meet people who want to sell. Every trade is a voluntary exchange: a buyer agrees to pay a price, and a seller agrees to accept it. When many participants compete on both sides, supply and demand shape where those agreements tend to happen.

Price discovery is the process by which the market figures out what an asset is worth right now. No single authority sets the “correct” price. Instead, prices emerge from the continuous stream of orders, trades, and new information. When buyers are more eager than sellers, prices tend to rise; when sellers outweigh buyers, prices tend to fall. That tug-of-war is visible in real time on any liquid market.

Most retail and institutional trading does not happen by shouting across a physical pit. Exchanges and similar venues act as intermediaries: they bring buyers and sellers together, enforce rules, and often provide the systems that match orders and settle trades. You interact with the market through prices and order types they display, but underneath you are always joining a queue of real counterparties.

The bid/ask mechanism is how that queue becomes two columns of numbers. Bids are prices buyers are willing to pay; asks (or offers) are prices sellers are willing to accept. The best bid is the highest buy price currently resting in the book; the best ask is the lowest sell price. The gap between them is the spread. A tight spread usually means many participants are competing; a wide spread can mean fewer participants or higher uncertainty. The mid price (roughly halfway between best bid and best ask) is often used as a quick read of “where the market is,” but trades actually occur at bid or ask levels when someone crosses the spread.

Traditional markets such as stocks and forex follow the same logic. Stock exchanges match buy and sell orders for shares; forex platforms connect orders for currency pairs. Both rely on continuous matching during market hours (and sometimes extended or overnight sessions, depending on the venue). When the primary session is closed, you may see wider spreads or less activity because fewer orders are resting in the book.

Crypto markets apply the same principles with two important differences. First, major spot pairs trade 24 hours a day, seven days a week on global platforms, so the order book can refresh around the clock. Second, you still use an exchange (or similar service) to match orders, but settlement and custody involve digital assets and blockchain or internal ledger mechanics, depending on the product. The economics of bids, asks, and matching are familiar.

On XT and similar venues, you will see the same bid column, ask column, and trade tape you would on a traditional brokerage screen—only the asset and settlement layer change. Volatility and continuous global participation can make the book move quickly compared with a quiet stock after the bell, but the underlying skills transfer: reading resting liquidity, spotting the spread, and interpreting each new print as a completed match between a willing buyer and a willing seller.

Order matching is the engine behind the screen. When you place a limit order at a price that crosses an existing order on the other side, a trade can execute immediately. If your order does not cross, it typically rests in the book until someone else is willing to trade at your price or you cancel. Market orders (or aggressive limits) take liquidity from the book by walking through available bids or asks. The order book is simply the visible stack of resting bids and asks at each price level; the recent trades list shows executions as they happen.

Liquidity matters because it determines how easily you can buy or sell near the displayed price without moving the market against yourself. Deep books and steady flow of trades mean you can enter and exit with smaller slippage (difference between expected and actual execution price). Thin liquidity can mean wider spreads, jumpier prices, and larger impact from individual orders. Whether you trade stocks, forex, or crypto, you are always operating inside this same framework: buyers, sellers, an intermediary that matches them, and prices that update as new information and new orders arrive.

Observe on XT

Open XT.com and navigate to spot trading for the BTC/USDT pair. On the trading page you will see the order book panel, usually split vertically or stacked so you can read both sides at once.

Focus on color and side. The buy side shows bids—resting orders from participants who want to purchase Bitcoin—often highlighted in green. The sell side shows asks—orders from participants who want to sell—often highlighted in red. These are not hypothetical lines; they represent live interest from the XT user base and connected liquidity, updating as people add, cancel, or fill orders.

Notice how the best bid sits at the top of the buy column (the highest price buyers are offering) and the best ask sits at the top of the sell column (the lowest price sellers are demanding). The last traded price or mid shown elsewhere on the page relates to where the market has recently transacted or where the two sides almost meet. When a buyer is willing to pay at least what a seller is asking, the matching engine can execute a trade; that is how market price is expressed in practice—not as a decree, but as the outcome of overlapping orders.

Spend a moment comparing size at each level (often shown as quantity of BTC or notional value). Deeper stacks at nearby prices suggest more liquidity; sparse levels can mean the book will move quickly if large orders arrive.

Practice

Complete these steps on XT to connect the concept to what you see.

1. Open the XT spot trading page for BTC/USDT.
2. In the order book, identify the current best bid (top of the green / buy side) and the current best ask (top of the red / sell side). Write both numbers down.
3. Calculate the spread in USDT: subtract the best bid from the best ask (ask minus bid). If you prefer a percentage, divide that difference by the mid price (or the ask) and multiply by 100.
4. Watch the order book for 30 seconds without scrolling away. Note how prices, quantities, and ordering update continuously as new orders arrive and trades print.
5. Find the recent trades (or market trades) list. Observe how often new lines appear and whether trade sizes vary—this is the matching engine turning resting liquidity into completed transactions.

Optional: Glance at the 24h high/low or volume on the same page and relate them to the idea that all of that activity is just many rounds of buyers and sellers agreeing on prices through the exchange.

Checkpoint

Q1: What is the primary role of an exchange in modern financial markets?

• A) To guarantee that every asset will rise in value over time
• B) To set a fixed official price for each asset each day
• C) To match buyers and sellers and facilitate orderly trading according to venue rules
• D) To eliminate the need for bid and ask prices

Correct: C. Exchanges (and comparable venues) intermediate between participants, provide matching and often clearing/settlement infrastructure, and apply rules; they do not guarantee returns or replace the two-sided market.

Q2: In a typical order book, where do you find the best bid and best ask?

• A) The best bid is the lowest buy price; the best ask is the highest sell price
• B) The best bid is the highest buy price; the best ask is the lowest sell price
• C) Both are always equal to the last traded price
• D) The best bid and best ask are only visible after the market closes

Correct: B. Buyers compete upward (best bid = highest willing buyer); sellers compete downward (best ask = lowest willing seller). The spread is the gap between them.

Q3: Why does liquidity matter to someone trading on a spot market such as BTC/USDT?

• A) Liquidity determines whether the blockchain can create new Bitcoin
• B) Liquidity only matters for stocks, not for crypto
• C) Higher liquidity generally supports tighter spreads and smaller price impact when entering or exiting a position
• D) Liquidity ensures the exchange sets a fair price by decree each hour

Correct: C. Deep, active books mean more competition and smoother trading; thin liquidity can widen spreads and increase slippage. Crypto still follows the same economic logic as other markets.