CNS Pharmaceuticals (CNSP) shares were up 258% in Monday premarket activity after the company said it signed deals for a private placement financing likely to generate roughly $22.5 million.

Skycorp Solar (PN) stock was 84% higher after the company said late Friday it signed a share acquisition agreement Thursday to acquire the remaining 56% stake in Nanjing Cesun Power for about $20.2 million.

Global Business Travel Group (GBTG) shares were up 57% after the company's American Express Global Business Travel unit said it has agreed to be acquired by Long Lake Management in an all-cash deal valued at roughly $6.30 billion.

EBay (EBAY) stock was 10% higher, a day after GameStop (GME) said it submitted a non-binding proposal to acquire all outstanding shares of eBay for $125 each.

Krystal Biotech (KRYS) shares were up 6.3% after the company posted higher Q1 net income and revenue.