Bittrex sellwalls for altcoins? Bug? 220000 Bitcoin sellwall

[cryptosleeper]

Since 2 weeks there are multiple huge sellwalls for coins like:
For example:
Sia 3500 Btc
XMY 500 Btc

I was wondering the past weeks why some people put up such huge sellwalls lately because i havent seen that in the past year (atleast not permanently)

But now, checkout STORM on bittrex.
Sellwalls with overall 227877 Bitcoin = around 1.85 Billion USD.
How is that possible? STORM has a market cap of 172 Million USD.

What do you think? Bittrex DB Sellwall calculation bugged or something else?

Looking forward to your opinions

cheers