John Bull can take anything but not less than 2%” by economist and journalist Walter Bagehot:

The phrase “John Bull can take anything but not less than 2%” points to a pivotal element of investor psychology: the intolerance to very low returns on safe assets. “John Bull” refers to the generic investor, specifically the English public, who is renowned for being pragmatic about finance. The saying indicates that although investors may ride out different economic storms or assume reasonable risk, they will ultimately revolt if their safest investments, such as savings accounts or government securities, return minimal amounts (historically approximately or less than 2%).
Why “Not Less Than 2%
Historically, a 2% return was an extremely modest but acceptable return from low-risk investments that would preserve purchasing power. When returns drop below this perceived level, investors grow impatient. They believe their money is not working for them, so they look to get better returns even if it means exploring riskier assets. This situation is commonly referred to as the “search for yield.”
Example: The Post-2008 Era and “Search for Yield”
Think about the era after the 2008 global financial crisis. Central banks around the globe, such as the Bank of England and the US Federal Reserve, sharply reduced interest rates to levels close to zero and embarked on Quantitative Easing (QE) schemes. This saturated the market with liquidity, rendering safe assets such as government bonds yield negligible, at times even negative, real rates (after inflation).
Confronted with this, “John Bull” – individual savers, pension funds, and institutional investors in this instance – saw their conventional, safe income sources reduced to a fraction. Their response was one with the words of the proverb: they couldn’t “take” such low returns.
This led to a general “search for yield,” driving investors into:

• Dividend-paying stocks: Even if the firms were less stable.
• “Junk bonds”: Riskier corporate loans with better interest rates.
• Property: Motivated by cheap mortgages and potential rental income or appreciation.
• Alternative investments: Including private equity, venture capital, and even cryptocurrencies, all with the promise of greater, though riskier, returns.
  This collective change pumped asset values in these riskier areas, illustrating the way avoidance of ultra-low returns can propel investment into speculative fields and create new financial bubbles. The proverb is a reminder that investors have a psychological bottom to acceptable returns and that pressures below it may induce unintended and sometimes unstable market activity.