Price is the value of one unit, but by itself it says little about the size of a project. A low-priced token may have a very large supply, while an expensive coin may have limited issuance.
Market capitalization is usually calculated as price multiplied by circulating supply. It is useful for rough size comparisons, but it is not the amount of money actually invested in the asset.
Twenty-four-hour volume describes trading activity. High volume can make execution easier, although its quality depends on venues and market structure. A volume spike should be compared with price movement and news context.
Do not decide from one percentage change. Compare several periods, liquidity, supply, holder concentration and the risks of the specific protocol.