Risk-off is the opposite mood — the moment fear takes hold. When people suddenly get nervous (bad economic news, a shock event, a wave of uncertainty), their instinct flips from growing their money to protecting it.
So they sell the risky, fast-moving things first and huddle into what are called safe havens: cash, government savings bonds, the US dollar, and gold. Because crypto sits right at the far, wild end of the risk scale, it usually falls the hardest and the fastest when the mood turns sour.
Back to the party: risk-off is the moment someone shouts fire. Everyone heads for the exit at once — and the stampede itself makes the fall worse than the original scare.