Why altcoin diversification does not protect you: ten longs are one position

"Don't put all your eggs in one basket" — so a trader opens longs on five to ten altcoins at once: if one coin fails, the others will carry. In crypto this works much worse than it seems. Here is the data on why ten same-side altcoin positions are one position.

Altcoins move together

Over the last ~100 days altcoins' hourly moves correlate with Bitcoin at about 0.5. On normal days about 69% of alts move the same way as Bitcoin. On its big-move days — 89%. Diversification disappears exactly when you need it most.

What market-wide moves look like

For each of 44 coins TPR-72 issues, every three days, the range price stays inside with ~80% probability. If coins moved independently, about 8 of 10 would stay inside every window. In reality the picture is two-humped:

In normal windows 85% of coins stay inside their range. But about once every 3 weeks the market makes a joint move — and almost every coin breaks its bounds at once. When Bitcoin broke its range, on average about 73% of altcoins broke theirs in the same direction.

What it means for a portfolio

Five longs on different altcoins, each with a stop worth 1% of the deposit, are not five independent 1% risks. In a joint drop almost every stop fires together, and instead of "one trade lost 1%" it is "the account lost 5% in an hour". Without stops — more.

What actually reduces risk

• A total risk limit per side, not only per trade.
• A stop on every position — beyond the coin's normal move (how to set it).
• Fewer simultaneous positions, each with a clear idea, instead of "ten just in case".
• Leverage with room: in a joint move liquidation hits every position at once (what leverage is safe).

Can a market-wide move be predicted?

No. We tested dozens of features — volatility, volume, open interest, funding, sentiment — none predicts such moves better than a coin flip. News or a liquidation cascade are not visible in advance. So prepare with position size, not a forecast: a joint move must cost a known, acceptable amount.

Method. Hourly Binance USDT-M futures candles for 44 coins over the last 230 days. A window starts at every hour; "price reached the level" means at least one candle touched it with its high or low. Longs and shorts are counted together. "Typical altcoin" is the median across all coins. This describes the past market, not a promise about the future.