Quantum computing may seem like a far-fetched technology, but the reality is that it's rapidly progressing to the point where it's starting to become useful in many applications. These investors should position themselves accordingly, as quantum computing could have a huge upside if investors pick the right stocks. I've got three stocks that I think are best positioned for quantum computing success. Investors should maintain some exposure to these stocks in case their breakthroughs cause them to go parabolic. IonQ IonQ (IONQ +2.49%) is one of the leaders of the quantum computing race. Its leadership status comes from its world-record holding system, which delivered 99.99% fidelity in a common test that quantum computing companies use to test accuracy. This is a huge deal, because the primary reason why we don't see more widespread quantum computing is its relative inaccuracy. IonQ believes that the 99.99% threshold is good enough for the company to start scaling its device to have millions of qubits by 2030. For reference, it plans to implement this technology to build a 256-qubit system this year. Should IonQ develop an accurate quantum computing system with millions of qubits by 2030, it could take the world by storm and be one of the top-performing quantum computing stocks, especially in applications where perfect accuracy is critical. NYSE: IONQ Key Data Points However, the reason why IonQ has achieved this incredible accuracy figure is the architecture it's designing its computer around. It's using a technology called trapped ion, which trades accuracy for speed. There are other quantum computing techniques, namely superconducting, that deliver slightly less accuracy but far better speed. That's the path that my other two picks are taking, and I think having exposure to both types is key to having long-term quantum computing investment success. Alphabet and Microsoft Alphabet