The spread is the gap between the best price a buyer is currently willing to pay and the best price a seller is willing to accept. It's the immediate cost of getting in and out of a position — if you buy and instantly sell, the spread is roughly what you lose.
Why it matters more on longshots
A spread in cents is easy to read wrong, because the same number means very different things at different prices. A 3¢ spread on a market trading at 50¢ is small — about six percent of the price. The same 3¢ spread on a 6¢ longshot is half the price. You'd need the market to move dramatically in your favour just to break even on the cost of entry.
That's why PrismTick shows spread as a percentage of price, not just in cents — so you can compare the real cost of entry across markets at very different price levels.
How to use it
Treat a wide spread relative to price as a warning that the market is thin or neglected. It doesn't mean avoid it — sometimes the neglect is the opportunity — but it does mean the price you see isn't the price you'll get, and you should size accordingly.
FAQ
What is the spread on a prediction market?
The spread is the difference between the highest price a buyer will pay and the lowest price a seller will accept. It represents the cost of entering and exiting a position immediately.
Why does spread matter more on longshots?
A fixed spread is a larger share of a low price. A 3¢ spread on a 6¢ market is half the price, but on a 50¢ market it is only six percent — so the same spread eats far more of your expected value on a longshot.