There has been a lot of speculation over why Bittrex suddenly and without reason delisted Bitshares (BTS) on October 13. This announcement from Bata -also delisted- might help explain it.
October 15, 2017 | Bata Cryptocurrency (BTA) Bata has been traded on Bittrex since 11/20/2015.
October 3rd 2017 - a market deletion notice appeared on the Bittrex exchange for the Bata market.
**Bittrex asked Bata development to explain the shares concept ** - referring to a testing announcement Profit Shares. Explanation was provided directly to Bittrex contacts.
Bittrex asked why Profit Shares was not considered as a security. Then proceeded to ask for a lawyer's memo. Bittrex requested that a US Attorney was required to issue the Memorandum.
It was made clear to Bittrex that Profit Shares is an independent project from BATA. Profit Shares is not a token. It's a private crowd-funding platform. " (Bold added for emphasis)
https://bata.io/news Quote taken from PDF statement.
The reason may in fact be the idea -much discussed- that Bittrex is distancing itself from companies that might be considered a security. That argument could be furthered by the delisting of Darcus as well.
"Darcrus is an asset issued on the NXT blockchain that will allow its holders to receive rewards via disbursements that are assigned through a Proof of Holding reward system (which is similar to the master node payment system found in DASH). The reward system can be based on a buyback program on an exchange or disbursement via the NXT’s & Waves’ native systems. " (Bold highlighted added for emphasis)
http://cryptoscreener.com/coins/DAR/
Three of the coins delisted all shared a concept of "shares," in BitShares case this is really only in name as Bitshares has already passed the been put on the clean token list.
https://www.txsrb.org/single-post/2017/08/31/Current-Clean-Token-List-our-opinion
The Bittrex Bitshares market is now suspended, but there was a report of a positive meeting Friday with more talks among the parties this week so all hope may not be lost. Until an official announcement those rumors are simply speculation, and should be taken with a grain of salt to not add to the uncertainly around the issue.