Market vs Limit Orders
Which are you willing to give up: the price, or the certainty of getting filled?
The idea
A market order prioritizes execution; a limit order prioritizes price but may not fill.
In the real world
A limit buy below the market waits, while a market buy crosses the spread now.
Going deeper
Every order chooses between certainty of execution and certainty of price, and there is no type that gives both. A market order says fill me now at whatever it costs; a limit order says fill me at this price or not at all.
Which is correct depends on what failure would cost. Needing to be out before an announcement makes an unfilled limit order the worse outcome, so paying slippage is rational. Accumulating a position with no deadline reverses it. The mistake is not choosing wrongly but not noticing that a choice was being made.
Where it stops applying
Stop orders complicate this: a stop becomes a market order when triggered, so it carries slippage exactly when markets are moving fastest and depth is thinnest.
Why it matters
Every order is a choice between those two, and there is no order type that avoids the trade.
Try this today
Choose whether certainty of execution or price control matters more.
Test yourself
You need to be out of a position before an announcement in ten minutes. Which order type, and what are you accepting?
Show the answer
A market order, accepting whatever price the book gives you including slippage. A limit order protects the price but may not fill, and an unfilled exit is not an exit. Certainty of execution is what you are paying for.
Learn this in the feed Answering from memory, then again days later, is what makes it stick.