Bitcoin is used much more actively in the darknet than the privacy-oriented cryptocurrency Zcash. This is stated in a study by Rand Corporation commissioned by Electric Coin Company.
Representatives of Rand Corporation emphasize that "the presence of Zcash in the darknet is negligible." According to them, in this segment, the coin developed by Electric Coin Company is a “less attractive option” for users than, for example, Bitcoin or Monero.
Analysts have studied three areas of the illegal use of cryptocurrencies: money laundering, terrorist financing, and trade in illicit goods. It turned out that in all these areas Zcash is less in demand in comparison with other popular coins.
So BTC is represented in most darknet marketplaces. Monero (XMR) and Litecoin (LTC) are also quite in demand.