Sort:  

It can happen because more smartcoin have been 'settled' than issued/shorted W/W.

Settlement is when BTS collateral backing the smartcoin is released, after which the smart contract destroys the smartcoins which results in a lower supply.

Coin Marketplace

STEEM 0.22
TRX 0.26
JST 0.039
BTC 105527.26
ETH 3401.76
SBD 4.64