Holding vtr in your own wallet is safer than Bittrex.
Clearly Morantis hasn't used the 2FA in the wallet - a first for any crypto project. You also get the benefit of earning free VTRs for staking if you hold the funds, otherwise you are just giving free VTRs to Trex.
Using the wallet, 2FA always protects your funds, even when staking. I've used it loads of times and it's rock solid.
As second line of protection, the wallet is also HD enabled, so remembering a series of random words means you can get your wallet back in minutes if your pc gets corrupted or you get locked out by malware
Links to videos on using the 2FA are on the vtorrent.info website