Arena Blog

The Coinbase Premium Index is read as a thermometer for US demand. It measures a price gap, not a flow — and its denominator is not a dollar. What it can carry, where it breaks, what the Korea premium reveals about it, and the six tests a backtest needs.

Twenty One Capital holds 43,514 bitcoin and trades at either a 41% discount or a 26% premium, depending on who is counting. Where the company came from, how its engine works, and why mNAV needs four labels.

Young coins without 200 weeks of history skip the 200-week filter automatically. We tested the obvious fix across 207 coins — it made everything worse.

The Bitcoin liquidity fair value chart shows R²=0.85 — and claims BTC is "348% above fair value". We ran the cointegration test. It fails.

DCA vs. lump sum for Bitcoin? Across 346 historical entries the lump sum won 60 % of the time — but DCA halved the downside. The distribution instead of an opinion.

Oracle manipulation drained millions from Ostium — not through a contract bug, but through bad data. The failure modes when DeFi protocols trust their price feeds.

Persi Diaconis shows a simulation can run for thousands of hours, look stable, and still be wrong. What he actually said about convergence and proof.

An AI swarm turned $1,000 into nearly a million? The number falls apart at its own source. Why consensus from correlated simulations is not an edge.

Look-ahead bias corrupts backtests when macro data is revised after the fact. Why we rebuilt our regime history to be strictly point-in-time — and proved it.

Bitcoin has no native yield. Every advertised BTC yield is a sold option, a loan, or a token emission. And with the income ETFs, the window decides whether the answer flatters or destroys.

Market data licensing is tiered, and the decisive line runs between derived values and raw prices. What that costs — and why we're switching off four asset classes for now.

Daily backtests compute the signal from the close and fill at that same close — a price you can no longer trade. We recomputed 7,000+ trades twice (close fill vs. next open) to size the distortion. Result: smaller than the myth.