A share of stock is a literal, legal sliver of ownership in a real company. When you buy one share of a business, you own that fraction of it — its factories, its cash, its future earnings, all of it, scaled down to whatever percentage one share represents. Stock trading is the business of speculating on how the price of that ownership stake changes, which turns out to be a very different game from simply owning it.
What a share actually gives you
Buying a share entitles you to three things, in theory: a vote at shareholder meetings (almost no retail trader ever uses this), a claim on any profit the company decides to distribute as a dividend, and — right at the very back of the line, behind every lender and bondholder — a claim on what’s left if the company is ever wound down. None of that is why most people trade stocks day to day. They trade them because the market’s opinion of what a share is worth changes constantly, sometimes by a lot, and that change is tradeable on its own.
Trading a stock versus owning a business
These are the same instrument used for two genuinely different purposes, and mixing them up is where a lot of beginners go wrong. Investing is a bet on the business — will this company be worth more in five years, based on its earnings, its competitive position, its management. It’s slow, it’s fundamentals-driven, and a bad week in the share price barely registers. Trading is a bet on the price — will the market’s opinion move up or down over the next hours, days, or weeks, regardless of whether the underlying business changes at all. A great company can be a terrible trade if you buy it the day before a disappointing earnings call; a mediocre company can be a great trade if it’s oversold and due for a bounce. The stock doesn’t know which game you’re playing — you have to.
What actually moves a stock’s price
- Earnings and guidance. Quarterly results move stocks more than almost anything else — and it’s usually the forward guidance, not the reported numbers, that does the real damage or delivers the real pop (our earnings-season guide goes deep on this).
- Sector and index moves. Stocks rarely move alone. A rate-sensitive sector sells off together when yields rise; a single company's stock often just goes along for the ride of whatever its whole industry is doing that day.
- Broad macro conditions. Interest rates in particular — higher rates make a company’s future earnings worth less today, which is a big part of why growth stocks are so rate-sensitive.
- Buybacks, insider activity, and index changes. A company buying back its own shares is a persistent source of demand; a stock getting added to a major index triggers real, mechanical buying from every fund that tracks it.
- Plain supply and demand. Sometimes a stock moves simply because more people want to sell it than buy it at the current price, with no new information at all — sentiment and positioning are real forces, not just noise.
Market cap and why liquidity matters
A company’s market capitalization — share price times shares outstanding — is a rough measure of its size, but for a trader it’s really a proxy for something more practical: liquidity. Large-cap names trade enormous volume every day, which means tight spreads and the ability to get in and out of a position without moving the price yourself. Small-cap stocks can move 10-20% on ordinary days precisely because there isn’t much volume behind the move — the same size order that’s invisible in a mega-cap can swing a small-cap’s price meaningfully.
Going long, going short
Buying a stock because you expect it to rise is going long — the position most people are familiar with, with a simple risk profile: you can lose what you put in, and no more. Short selling is the mirror image — you borrow shares you don’t own, sell them at today’s price, and aim to buy them back later at a lower price to return them, pocketing the difference. It’s a legitimate way to profit from a decline, but the risk profile is genuinely different.
How this actually works on a CFD platform
On a platform like Horizon Capital, stock positions are typically traded as CFDs — contracts for difference — rather than by taking delivery of the actual shares. You’re trading the price movement itself: no share certificate changes hands, no shareholder vote, and dividends are usually reflected as a cash adjustment to your position rather than an actual payout. What you keep from direct share ownership is the part that matters for trading — full exposure to the price move, in both directions, usually with leverage available and without needing the full value of the position in cash upfront.