Plain definitions of 40 stock market and paper trading terms. Each has a worked example in dollars and a way to practice it. JagSim is a free simulator with $100,000 of virtual money and real-time market data. Pick a term, then go try it.
An order to buy or sell right now at the best available price.
An order that only fills at your chosen price or better.
An order that waits for a price you set, then buys or sells at the market.
An order that sells automatically if the price drops to a level you set.
How long an order stays open: until the close, or until it fills or you cancel it.
Betting a price will fall by borrowing shares to sell now and buy back later. Explained here; JagSim does not offer it.
Trading before the 9:30 AM open, from as early as 4:00 AM New York time.
Trading after the 4:00 PM close, usually until 8:00 PM New York time.
Why coins trade every hour of every day, and what that changes.
The gap between the highest buy price and lowest sell price.
The gap between the price you expected and the price your order filled at.
Reading the open, high, low and close of each period from one candle.
The average closing price over recent periods, drawn as a line.
How many shares or coins changed hands in a period.
How much and how fast a price swings up and down.
An account that buys only with money you have, with no borrowing.
How much you can spend on new positions right now.
Buying part of one share to invest a set dollar amount.
What you paid per share across every buy of one stock.
Profit on what you still hold, and profit made final by a sale.
How much money a trade or account has made or lost.
Everything you hold: your cash plus all your open positions.
Deciding how much money to put into a single trade.
Spreading money across many investments so one bad result hurts less.
The fall in an account from its high point to the low that follows.
Trading back to the mix you planned after prices move it.
The short code that identifies a stock, fund or coin.
What all of a company's shares are worth at today's price.
A share price divided by a year of earnings per share.
A payment a company makes to its shareholders, usually in cash.
A year of dividends as a percentage of the share price.
The first day a stock trades without its next dividend.
More shares at a lower price, with the same total value.
A fund that holds a basket of investments and trades like a stock.
A fund that holds the stocks in an index to match its return.
The index of about 500 of the largest US companies.
Practicing trades with virtual money instead of real cash.
Opening and closing trades within the same day.
A long rise in prices, often 20% or more from a low.
A long fall in prices, usually 20% or more from a high.
Last updated: October 2026 · Educational only. Not investment advice. JagSim is a simulator, not a broker.
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