Four simulated stocks, a live order book, real-time news events, and a portfolio that persists between visits - all with zero real money. Learn bids, asks, limit orders, and more by doing, not reading.
Paper balance: $10,000.00
| Sym | Shares | Avg Cost ? | Price | Mkt Val | P&L ? |
|---|---|---|---|---|---|
| No open positions yet | |||||
Random events that move individual stocks, sectors, or the whole market.
Unlock badges as you learn and trade. Hover for details.
■Buyer initiated ■Seller initiated ★Your trade
Now that you understand bids, asks, and order books, open an account with Robinhood to start trading stocks for real.
Start Trading on RobinhoodSix core concepts every investor must understand before placing a real trade.
The bid is what buyers will pay. The ask is what sellers will accept. When you click "Buy Market," you pay the ask. When you click "Sell Market," you receive the bid. These prices update continuously as traders enter and cancel orders.
The spread is Ask − Bid. It's an invisible cost on every trade. A $0.01 spread on a $100 stock is trivial (0.01%). A $0.50 spread on a $5 stock is huge (10%). High-volume, large-cap stocks have very tight spreads. Thinly traded stocks can have wide spreads that hurt you on both the buy and the sell.
The order book is a live record of every pending buy and sell order. Bids stack below the price; asks above. The depth bars show relative size at each level. Large walls of orders can act as temporary support or resistance - until they're cancelled or absorbed.
A market order fills instantly at whatever the market offers - fast but unpredictable in price. A limit order sets your price but may wait forever. A stop order triggers automatically at a threshold, converting to a market order for fast exits.
VWAP is the volume-weighted average price - the institutional benchmark. Trading above VWAP is considered bullish; below is bearish. RSI measures momentum on a 0–100 scale: above 70 signals potential exhaustion (overbought), below 30 signals potential reversal (oversold).
P&L (Profit & Loss) is unrealized while a position is open, and realized once you close it. Unrealized P&L changes every tick. Position sizing - how much you risk per trade - is arguably the most important skill in trading. Even a strategy with a 40% win rate can be profitable with proper sizing.
You tell the simulator "buy 50 shares of MMBX at market." In real life, your broker routes this to an exchange or market maker.
The exchange's matching engine finds the current lowest ask. If someone is selling at $142.51, your market buy executes at exactly $142.51.
The trade executes in milliseconds. Your account is debited the purchase price. The seller is credited. The trade appears on the public Time & Sales tape.
Trades execute instantly but legally settle one business day later (T+1 in the US since 2024). Your broker handles this automatically.
Every market buy lifts the ask - price ticks up. Every market sell hits the bid - price ticks down. Volume and order imbalance drive the trend you see in the chart.
A buy limit at $138 when price is $142 sits in the book visible to other traders as a bid. If price falls to $138, you get filled - otherwise it waits indefinitely until cancelled.