Quantum computing is a pre-commercial technology that uses quantum mechanical effects to solve problems impossible for classical computers. Stocks in this space are highly speculative -- most companies have minimal revenue and depend on research contracts.
Classical computers use bits (0 or 1). Quantum computers use qubits, which can be 0, 1, or both simultaneously (superposition). This lets them process exponentially more combinations at once -- making them theoretically ideal for cryptography, drug discovery, and optimization.
We are in the 'NISQ era' -- Noisy Intermediate-Scale Quantum.
Current machines (100-1000 qubits) are too error-prone for commercial advantage.
Fault-tolerant quantum computing (millions of logical qubits) is 5-15 years away.
Google's 'Willow' chip in 2024 solved a specific benchmark faster -- not yet practical.
IONQ, RGTI, QUBT are speculative micro/small caps -- extreme volatility.
IBM and GOOGL have quantum divisions but it's a tiny part of revenue.
These stocks move on headlines (government contracts, research papers).
Keep position sizes very small (max 1-2% of portfolio) given the risk.
Related: AI & Machine Learning Sector • sector_technology • Position Sizing