Bitcoin advocates frame it as "uncorrelated" with traditional markets. The data, at least since 2020, says otherwise.
When the Fed has been cutting rates and adding liquidity (2020-2021), Bitcoin has rallied alongside stocks. When the Fed tightens aggressively (2022), Bitcoin has sold off — sometimes more than stocks. The correlation between Bitcoin and NASDAQ tech stocks has exceeded 0.6 in recent years.
For portfolio construction: if you already hold growth/tech stocks, Bitcoin may add less diversification benefit than expected. During Fed tightening cycles, both tend to sell off together. For diversification, bonds historically provided better ballast during tightening cycles.