There is quite a bit of demand for Bitcoin over illegal goods markets. The thing is though, buying bitcoins in the ways the black market would prefer usually comes at a premium nd other than that, the fact that correlating Bitcoin transactions to the type of activity they support ilmakes it difficult to compare the effect darknet markets have on the price over speculative markets.
As the rumor said, bitcoin became a payment of transaction in deep web. Taking the system of bitcoin, we all know that it does not need bank or any middleman for every transaction. That is what they need in deep web for anything they are doing, even if it is good or not. They are having negotiation under the influence of bitcoin as a payment since it cannot be detected.