Coinbase (NASDAQ:COIN) President and Chief Operating Officer Emilie Choi believes the crypto exchange can control its operating expenses even with volatility surrounding digital asset markets, she says at the Goldman Sachs U.S. Financial Services Conference. Some of these investments include custody, trading, derivatives, everything that institutions want, she says. Choi also notes that there is retail interest for a subscription based service on the Coinbase (COIN) platform. On mergers & acquisitions, Choi says "we've been quite aggressive with M&A," with tons of robust global M&A opportunities ahead. For 2022, Choi thinks parts of DeFi and non-fungible tokens are a long-term trend that could end up being really big. Shares of COIN climb nearly 3.5% as Bitcoin (BTC-USD +5.8%) jumps back over $50K level. Previously, (Nov. 30) Coinbase will acquire Unbound Security.