When they say that 'Greyscale' sold BTC and mention the BTC ETF daily outflows, who exactly is doing the selling ? Is it many clients who use Greyscale or is it Greyscale themselves ?

I'm just confused who does this whole thing work. For example if I read that 'Greyscale' sold BTC worth of 200 million today what does that mean? Does it mean that Greyscale CEO + management sold BTC that Greyscale legally owns for its own usage or does it mean that , for example 350 clients sold their BTC holdings that they had in Greycale and the amount of these client's sell orders is around 200 million ?

The question is does Greyscale management have any say when they sell BTC or it's entirely up to their clients? Or does Greyscale also have its own BTC that is separate from its client's BTC?