the SIG already got enough vote on bit-z, when will they open the trading for SIG, now the trading volume on hitbtc is too small, its hard to buy and sell

I think what's important right now is for them to focus on the roadmap. Bit-z will be listing SIG soon and other exchanges will follow,

CoinMarketCap usually required 100K USD trading volume before listing a new token so as soon we hit the required trading volume they will list SIG.

Only hitbtc  is not enough. For listing on coinmarketcap need more exchanges and trading volumes.

I agree with you, need more than one exchange to be able to SIG list to coinmarketcap. I think with a large ico acquisition is not difficult to enter the SiG to a large market like bittrex or binance.

I have heard that the SIG will be listed on bit-z.com, which is a reliable exchange based on Hongkong, China, I checked its website and found SIG has got enough votes to be listed, but there is no further information about when to start trading, any news from the dev team about this listing?

Please don't push Spectiv to get listed. The markets are bloody as hell. A listing will only facilitate bounty dumping along with the weak hands, selling at a loss. Crypto buyers are all waiting on the sidelines to see when the bear cycle ends.

are  VCs firms invested ?

right man. these days, binance and bittrex are not listing easily tokens. especially binance. i know they require a product before a single token be listed.
but i think they can easily be listed on kucoin and qryptos. those are great exchange too.