We acquire a unique dataset of high-frequency traded prices for bitcoin call and put options from the Deribit cryptocurrency derivatives exchange, by 15-minute sampling via the application programming interface. We use these prices to construct a term structure of bitcoin implied volatility indices using a variance swap fair-value formula that is employed by the CBOE for the VIX, an index commonly referred to as the ‘investor fear gauge’ for the US stock market. Employing over seven million option prices, we construct the bitcoin implied volatility indices with maturities from one week to three months, sampled every 15 minutes from March 2019 to March 2020. We discuss the features of the index and the associated bitcoin variance risk premia, with three different regular time partitions for realized variance, viz. 15-minutes, hourly, and daily. We also examine the relationship between bitcoin’s 30-day realized variance, volatility index, and variance risk premium, with their equivalent for US equities, oil, gold, the USD/EUR exchange rate, and the 10-year US Treasury note.