Is this a glitch? Or do I not understand how this works lol

Hello everyone I am new to crypto, I thought I understood the basics but a few hours ago I noticed that around $100 that I had purchased of solana on CoinBase suddenly dropped to $67 in a minute but this whole time Solana has been at around $152 so why did it just tank down like this. ( it also goes up in a second bc i purchased $20 more of solana yesterday, but havent sold anything.