You don't trade "on the stock market" directly — you open an account at a broker (a regulated middleman), and your orders travel through it to the exchanges. Two choices define your beginner experience: which order type you click, and which account type you're clicking it in.
The two orders you'll actually use
A market order says "buy (or sell) right now, at whatever the going price is." You're guaranteed to trade; you're not guaranteed the price — in a fast or thinly traded market, "the going price" can be worse than the quote you saw. A limit order says "trade only at my price or better." You're guaranteed the price; you're not guaranteed to trade — the market may never come to you. Every other order type on the menu (including the stop order, which becomes a market order once price touches your trigger — the standard way traders pre-plan an exit) is a combination of those two guarantees. These definitions match the SEC's own investor-education pages, linked below.
Cash vs. margin
A cash account trades only the money you deposited. Simple, and your maximum loss is what you put in. A margin account lets you borrow from the broker against your holdings — amplifying gains, losses, and stress alike, and opening the door to losing more than intended. U.S. margin accounts require a $2,000 minimum to open, and the broker can forcibly sell your positions (a margin call) if losses run. Beginners have no business borrowing to trade; a cash account is the honest starting point.
The 2026 rule change (worth knowing because everyone still talks about the old one)
For 25 years, U.S. rules labeled anyone making four or more day trades in five days in a margin account a "pattern day trader" and required them to hold $25,000 minimum — the famous PDT rule that shaped (and warped) a generation of small accounts. That rule was eliminated effective June 4, 2026 (FINRA Regulatory Notice 26-10): the $25,000 minimum and the day-trade counting are gone, replaced by a framework where your intraday buying power is based on real-time margin in the account. Two practical notes: brokers are allowed to phase the change in until October 2027, so your broker's rules may still be transitioning — check them directly; and the change removes a barrier, not the risk. The $25k rule never made day trading dangerous; leverage and inexperience did, and both survived it.
Check yourself: you want to sell a stock if it ever drops to 45, but you're not at the screen all day. Which order, and what's the catch?
A stop order at 45 (a "stop-loss"). The catch: when triggered it becomes a market order, so in a gap or a fast drop the actual sale can happen below 45. It's still the standard tool for pre-planning an exit — Lesson 6 explains why pre-planning is the whole game.