The investment bank bought ~10 million shares in November of 2020 when Fastly was trading in the $60-$80 range, then another 3 million shares last February near $25.
Looks like they're finally throwing in the towel. A 13G form received on April 8 shows that they sold ~11 million shares, or 84% of their stake. Now, Morgan Stanley only owns 2.09 million shares.