OP tokens worth $278 million to be unlocked on May 31, representing 3.6% of total supply

According to Token Unlocks, Optimism will unlock 154,618,822 .65 OP tokens on May 31, or $278 million, representing 3.6% of the total supply. Of these, 81,604,379 OPs were unlocked by core contributors and 73,014,444 OPs were unlocked by investors. 

In addition, the Optimism governance account tweeted that OP circulation will increase on May 31, and in the two weeks prior to that, users may notice a large number of on-chain transfers, which are planned transactions in preparation for distribution, as seen in the estimated circular supply allocation.