300k coins were not dumped, there was barely even 200k in all of Bittrex's wallets. Also 48% of all coins were staking before the dump, now its 37%.
Yes, you're right. Made a mistake watching the volume. The Volume is around 400k but there was also a lot of buying before. But the problem is: Even if "just" 150k were dumped it doesn't make it really better. It was pumped and dumped. And there is always the problem that guys who hurt a project like this, whoever they are, take the money and leave. It's always the time after a dump the Devs will show if the project is legit or not. Never saw that the price recovered fast after a dump like this.