Slippage, Liquidity, and Spreads
You can be right about an event and still make a poor trade if the market is thin, the spread is wide, or your order moves the price too much.
That is why slippage, liquidity, and spreads matter. They determine how easy it is to enter and exit a position at a fair price.
What they mean
- Liquidity is how much size the market can absorb without moving sharply
- Spread is the gap between the best available buy and sell prices
- Slippage is the difference between the price you expect and the price you actually get
How it works
In a deep market, you can often trade size with little price impact.
In a thin market, even a modest order can sweep through multiple price levels and worsen your average entry price.
Why it matters
These three factors affect:
- your real trade cost
- how easy it is to change your mind later
- whether small informational edges are actually worth trading
Example
Imagine you want to buy YES in a market quoted around 0.55.
If there are only a few shares available near that price, your order may fill partly at 0.55, then 0.57, then 0.60. Your forecast might still be correct, but your entry quality got worse.
What traders should check
Before trading, look at:
- The best bid and ask
- How much size sits near those prices
- Whether the market has been active recently
- Whether your intended position is too large for the visible depth
FAQ
Is low liquidity always bad?
Not always, but it makes execution risk much higher and can distort prices.
Why do wide spreads matter?
Because they increase the cost of getting in and out, especially if you are not using patient limit orders.
What should I read next?
Read Limit Orders vs Instant Orders and Order Books vs AMMs.