Tick and lot size

Both Price (px) and Size (sz) have a maximum number of decimals that are accepted.

Prices can have up to 5 significant figures, but no more than MAX_DECIMALS - szDecimals decimal places where MAX_DECIMALS is 6 for perps and 8 for spot. For example, for perps, 1234.5 is valid but 1234.56 is not (too many significant figures). 0.001234 is valid, but 0.0012345 is not (more than 6 decimal places). For spot, 0.0001234 is valid if szDecimals is 0 or 1, but not if szDecimals is greater than 2 (more than 8-2 decimal places). Integer prices are always allowed, regardless of the number of significant figures. E.g. 123456.0 is a valid price even though 12345.6 is not.

Sizes are rounded to the szDecimals of that asset. For example, if szDecimals = 3 then 1.001 is a valid size but 1.0001 is not.

You can find the szDecimals for an asset by making a meta request to the info endpoint