What Really Moves the Market? Understanding Price Action Beneath the Surface

Most people think they understand the stock market. If more people want to buy a share, the price goes up. If more people want to sell it, the price goes down. That’s just supply and demand, right? Yes, but that’s only part of the story. The real engine room of the market is far more complex. If you’ve ever stared at a volatile price chart and wondered how that price is being set moment to moment, you’re not alone. To truly grasp what moves markets, we need to go beyond economics and dive into the mechanics of price action behind the scenes.

What is price action – what actually causes a share price to change?

At the most basic level, prices move because of orders being filled. Every price change on your trading platform is the result of a transaction between a willing buyer and a willing seller. When a buyer is willing to pay a higher price to ensure they get shares immediately, the price moves up. When a seller is desperate to offload and accepts a lower price, the price moves down.

This is where market orders and limit orders come into play. Market orders execute instantly at the best available price. Limit orders sit quietly in the order book, waiting for the market to come to them. When a market order hits the book, it consumes the available liquidity and that’s when prices shift.

So yes, supply and demand are the drivers, but it’s the type of orders and how they interact with each other that really causes the price to jump or dip.

How does order flow and hierarchy work behind the scenes?

Every exchange follows a set of basic rules that control how orders are matched. These are the two general ones that you’ll find common across all exchanges:

1. Market orders take precedence limit orders. If you’re willing to buy or sell right now, your order jumps the queue, and your order will be executed immediately.

2. Time matters. Orders are executed on a first-come, first-served basis. If you place a buy limit order at 13:00 for 100 shares, you will take priority over someone who placed the same order, but one second later.

Let’s say you want to buy share XYZ, which is currently quoted at R100. The order book might look like this:

• Sellers:
o 100 shares at R101
o 150 shares at R102
o 200 shares at R103

• Buyers:
o 80 shares at R99
o 120 shares at R98

If you place a market buy order for 100 shares, you’ll immediately get filled at R101 (the lowest price available from a willing seller). That action causes the market price to shift upward (this is the movement you’ll see on screen), because the R101 order is now gone. If other buyers follow with market orders, they’ll be paying R102 next. That’s how price rises, through market orders meeting pending orders.

The reverse happens when sellers are more aggressive. Market sell orders hit the bid side of the book, driving prices lower.

How do fundamentals, technicals, and sentiment influence this?

Now we’re connecting the dots. Fundamental factors like earnings, macroeconomic data, or news give investors a reason to want in or out. Technical analysis helps traders make timing decisions, spotting support levels or breakouts. Sentiment, whether driven by emotion, momentum, or social media buzz, amplifies it all.

But all these forces only affect the market when they result in orders. An analyst upgrading a stock doesn’t move the price. It’s only when investors start acting on that information – placing buy or sell orders – that the price actually shifts.

So, think of these factors as the motivation. The actual price change? That comes from the execution. The moment someone decides to act – that’s when the market responds.

Understanding price movement isn’t just about why – it’s about how.

Whether you’re a long-term investor or a short-term trader, knowing how orders flow and how prices adjust in real-time can give you a serious edge.

You’ll start to see beyond the candles on the chart. You’ll understand that every tick up or down is a vote being cast in a marketplace of urgency, fear, and conviction. And once you grasp that, you stop just reacting to the market – you start reading it.