A serious question

Why in the world would anyone investing in Grayscale sell all their bitcoins now when BTC is going up?

I tried to look up the reasons for why Grayscale is selling so much btc but it just doesn't make sense.

The reasons I found was:

Grayscale is charging 1.5% management fees

And

A lot of investors bought GBTC at a 40% discount

Both are not really a reason to sell it now, for weeks.

I'm sure that's not the whole (or any) reason, so maybe someone of you can clear this up for me, because at this point I have to put on my tinfoil hat and assume somehow the Grayscale boss got put under pressure to sell so Blackrock can accumulate massive amounts of BTC without sending the price to the moon (the reason why they want massive amounts is a different conspiracy I don't wanna discuss here).