A market order: available prices, not the picture’s price
A market order seeks to buy or sell at available prices. It generally aims for prompt execution, but the execution price is not guaranteed. The last transaction or best displayed quote may change before the order fills. A large quantity can execute at several prices.
Trading halts, missing counterparties and other restrictions prevent a universal promise of immediate complete execution. Available types, hours and policies depend on the venue and intermediary. The SEC source describes common stock orders, not every instrument in every jurisdiction.
A limit order: a price constraint without a fill guarantee
A buy limit permits a price at or below its limit; a sell limit permits a price at or above it. This constrains price rather than demanding a guaranteed fill. Suitable opposing interest and queue position still matter. A chart touching the level does not itself prove execution.
Specify quantity and time in force separately. Unfilled quantity may wait or expire under the instruction and applicable rules. A stop price is a different condition; do not assume that every order containing “stop” is an ordinary limit order.
| Instruction | Price condition | Not guaranteed |
|---|---|---|
| Market | Available execution price | A specific price or immediate complete execution in every condition |
| Buy limit | At the limit or lower | Any fill or the whole quantity |
| Sell limit | At the limit or higher | Any fill or the whole quantity |
Five units with an ask of USD 50.10
All numbers are fictional and commissions are zero in this table. Let bid/ask be USD 49.90/50.10 per unit. If five units remain available at that ask and nothing else changes, a five-unit market purchase costs 5 × 50.10 = USD 250.50. That is an educational snapshot assumption, not a guaranteed price.
A limit purchase of the same five units at 50.00 does not cross an ask of 50.10 and does not fill now. Neither choice is declared better: the instructions constrain different features of the outcome.
| Case | Buy boundary | Units filled | Cost, USD |
|---|---|---|---|
| Market with 5 available at ask | — | 5 | 250.50 |
| Limit with ask above limit | 50.00 | 0 | 0.00 |
Only part fills later
Suppose an offer for two units later appears at 49.98 and our order receives them with no queue ahead. Two units fill for USD 99.96; three remain. If the next available ask is 50.05, it exceeds the 50.00 limit, so that remainder cannot buy at this price.
This scenario assumes the remainder is still active. Prices alone cannot tell us whether it remains, expired or was cancelled. Check order status rather than drawing an assumed fill on a historical candle. No real order exists in this example.
| Time | Available ask | Filled | Remaining | Cost of this fill, USD |
|---|---|---|---|---|
| Initial snapshot | 50.10 | 0 | 5 | 0.00 |
| 2 units arrive; no queue ahead | 49.98 | 2 | 3 | 99.96 |
| Next offer above the limit | 50.05 | 0 | 3 | 0.00 |
What to record before comparing results
Keep desired price, permitted boundary and actual execution separate. Chart analysis can examine when a condition became known, but Student Wyckoff Pro does not submit or execute exchange orders. A paper exercise or educational table is sufficient here.
- Type, side, quantity and time in force are separate fields.
- A chart price does not establish available quantity or queue position.
- A partial fill is not a complete fill.
- Use actual fills for fees and slippage without counting the same cost twice.
Primary sources
Sources explain the mechanics and limitations; the editorial examples use invented numbers rather than market quotations.
Your next practical step
Student Wyckoff Pro helps you study closed bars and save your analysis. It does not execute trades; access and the Windows connection are explained in the guide.
Open the first-chart instructions ↗