Arena Blog

Five bull markets since 2010, one simple rule. The climb took 8 to 11 months every time. What got shorter is the way back to year-old prices, not because bitcoin falls faster, but because it rises less steeply.

The band softens the crash in Bitcoin, Ether and stock indices. In half of the large altcoins it brakes too little, and in gold not at all. 35 coins, three indices and gold, tested.

Measured by drawdown, the 2026 bear market was the mildest of bitcoin's big cycles: −53 % against −77 % to −93 % before. Measured in time, it was the worst: the low matched a price from five and a quarter years earlier, further back than any low since 2010. And against its own history, bitcoin was not cheap at any low since 2017. Three numbers for every bear market, and what each tells you before you call bitcoin a bargain.

A popular framework says: cut a strategy's position in half when its 90-day Sharpe drops below the backtest's 5th percentile, pause it at 1.5x the backtest drawdown. Simulated, those rules cut eight in ten healthy strategies to half size within three years and leave four in five strategies without any edge running through their first year. What to check instead.

Since 2011 Bitcoin has fallen 30 percent within a month 19 times. How often that happens today, how it fits with falling volatility, how far the drop usually went, and what that means for the size of your position.

Across 405 crypto pairs, buy and hold loses money on 83 % of them. What 197,435 backtests say about what a strategy does first, what decides whether it earns, and why the bar for any altcoin is Bitcoin.

"Stocks have recovered from every war" is true — for one country. After the April 1940 high the Dow needed four years and nine months to get back to even, in 1914 the exchange was closed for four and a half months, and St Petersburg, Vienna, Tokyo and Shanghai are missing from the statistics because their exchanges ceased to exist. Across 39 markets, a diversified investor is down in real terms after 30 years in 12 % of cases.

Across 18 midterm years since 1954 the S&P fell 17.7 percent from its high on average — but only 5 of them had a 19-percent drop inside the second half. What the number measures, how much of it reaches Bitcoin (through the S&P, not through yields), and why Bitcoin's own midterm-year bears come from the halving.

The most detailed factsheet among three providers checked lists hit rate, best trade and worst trade — but not how far the portfolio fell or for how long. Five questions that make a return readable.

The Richmond Fed tested 30 years of income data against a strict definition: a K appeared in 2002–06 and 2010–13, not after COVID. Why short stretches still last, and why no average can show one.

A grid bot had the flatter drawdown in 138 of 138 windows since 2017, ranges set in advance. Not because it trades well: because it never invests more than half the money. What that protection costs in rally windows, and what a hindsight range was worth.

We audited 40,000 of our own backtests — and benched several of our own strategies in the process. Here is what we killed, what we reactivated, and the uncomfortable core lesson: whether a strategy is "good" depends less on the strategy than on the asset class it runs in.