Fewer market makers, and a 24/7 contract on an asset that only trades 6.5 hours a day. When US markets are closed the perp is the only venue that moves, so the premium swings and funding follows it.
From Friday close to Monday open the cash market is frozen while the perp keeps trading. A gap in the underlying becomes a basis move you cannot hedge until the open.
Look at 24 hour volume: anything under a few million dollars will show rates you cannot fill. Compare the perp price with the underlying share, and check whether the venue can suspend the contract.
Our screener covers Binance, Bitget, Gate and Kraken, updated hourly, with a dedicated tokenized stock section and a negative funding list.