No one knows it's ATH until price had passed through it. I'm sure those selling after ATH would've sold during the ATH, no matter what time plan they had in place. No one likes to miss chances if they could take it. I think that was what happened. Again, it could also be that they couldn't sell before now because they couldn't unlock the wallets. May be they never figured out where they wrote down the private keys or password to the wallets until now. It could also be something totally unrelated to what I think. We never can pointedly tell though, except those involved tell their stories.