Ark Invest founder and CEO Cathie Wood did not invest in the ProShares Bitcoin Strategy exchange-traded fund (ETF) on opening day, according to Business Insider

Wood said about the ETF’s debut:

“No, we did not [invest]. We’re looking at this very carefully […] there are some tax ramifications we’d like to understand more having to do with contango versus more normal backwardation.”

The contango of the ETF refers to when the future price of the commodity is higher than the spot price. Backwardation is when the forward price of the futures contract is lower than the spot price in a downward trend.

This past June, Wood’s Ark Invest partnered with 21 Shares to file for its own Bitcoin (BTC) ETF. She is also no stranger to the equities market when it comes to investing in cryptocurrencies.

One of her funds, Ark Investment Management, was approved to invest in Canada’s Bitcoin ETF under the Ark Next Generation ETF. Ark Invest owns 8.3 million shares of Grayscale Bitcoin Trust (GBTC), with Bitcoin and Ether (ETH) making up a good percentage in Ark Invest’s portfolio.

In the spring, Ark Invest also added Coinbase stock to three of its ETFs, Ark Innovation ETF (ARKK), Ark Next Generation Internet ETF (ARKW) and Ark Fintech Innovation ETF (ARKF).

Wood said she is looking for the next FAANG investment to help her investors. FAANG is a stock market acronym describing the five biggest American tech stocks: Facebook, Amazon, Apple, Netflix and Google. The FAANG term was initially coined by Jim Cramer in 2013.

The Bitcoin Strategy ETF had the highest-ever first day of natural volume for an ETF, and the second-highest ETF on the overall volume on its first day of trading.