Why do you favor harsher sentencing for him?
As a hedge fund manager, losing money is not illegal. The only illegal thing he did was lie about it so that he could get them their money back.
It would've been perfectly legal for him to lose all his clients money in the hedge fund, make them aware of this fact, and reap the profits from his pharma business without dishing it out to his hedge fund clients.
As far as I can tell, Shkreli turned a technically legal "I fucked up and lost your money scenario" into a technically illegal I fucked up, lost your money, but got it back to you scenario.
If I was part of Shkreli's hedge fund, I would much prefer to be involved in the latter scenario than the former.
Sure, I could sue Shkreli to recoup some of my hedge fund losses, but this way they didn't need to.