Grayscale estimates that Zcash mining machines generate about twice Bitcoin miners' daily rewards and roughly four times more per unit of electricity. Zcash mining activity has risen to more than 2.5 times its level at the start of the year. Grayscale research head Zach Pandl said Zcash mining is currently highly profitable at prevailing valuations, with higher token prices lifting rewards and encouraging more computing power to participate. Grayscale said additional computing power can support network security. The comparison used Bitmain S23 Hydro and Bitmain Z15 Pro machines, assuming electricity costs of $0.05 per kilowatt-hour, continuous full-load operation and no transaction fees. Pool fees, cooling, other operating expenses and equipment costs were excluded, meaning actual profitability will vary. Bitcoin miners receive about $35 million in total daily rewards, compared with roughly $2 million for Zcash miners. Grayscale's Zcash investment products exceeded $500 million in assets on Sept. 8 and recorded more than $70 million in cumulative external inflows.