Quantum computing technology isn't so far out that investors can ignore it. It's coming faster than most people think, and in order to realize maximum gains, investors need to start positioning their portfolios accordingly to take advantage of what could be a massive industry. Currently, the quantum computing market has relatively few sales of early-stage systems, and most revenue is derived from research partnerships and contracts. However, by 2035, McKinsey & Company estimates that the quantum computing industry could generate up to $72 billion in annual revenue. That's a huge opportunity expected to emerge over the next decade, and widespread quantum computing could be available as soon as 2030. As a result, investors have no time to lose in filling their portfolios with top quantum computing picks, as the best gains will come in the early days of the rollout, when there's the most uncertainty about who will win. I've got three stocks that I think are fantastic quantum computing investments, and make for genius buys in April. IonQ IonQ (IONQ 2.15%) is my top pure-play quantum computing pick. IonQ has no other businesses outside of quantum computing; if it fails in this task, it's probably going to $0. That's a scary outlook, but if you look at its technology, IonQ looks likely to win in this space. It uses trapped-ion technology, which gives it an accuracy advantage over some popular quantum computing methods. It also recently unveiled its blueprint to build a quantum computer with 10,000 qubits -- a mark some consider the minimum threshold for a commercially viable quantum computer. NYSE: IONQ Key Data Points The military also selected IonQ (along with a handful of others) for its DARPA contract, which showcases IonQ's prowess when compared to several other leading quantum computing companies. I think this gives plenty