Arena Blog

Tomorrow, SpaceX is expected to do something no company has done before: raise roughly $75 billion in a single offering.

The most consequential Bitcoin payments story of the past year isn't a price chart. It's a transaction you'll never see.

LLMs don't trade profitably. But why would anyone expect them to? The honest answer is uncomfortable: nobody can see the future, and markets are explicitly the opposite of a forecasting machine — they're a mechanism for the ongoing negotiation of disagreement. On the Grossman-Stiglitz paradox, why one side of every trade is convinced it's smarter than the other, and why AI trading tools mathematically neutralize themselves the moment they become widespread.

A new strategy is live: Gerald Appel's MACD from the 1970s, now fully tunable (default 12/26/9). Two trade modes — classic signal cross or histogram flip — give you a reactive and a confirming variant from one indicator.

A new strategy is live: BB+RSI combines two classics into a strict mean-reversion setup. BUY only when price is at the lower Bollinger band AND RSI is oversold — two conditions, fewer false signals. Pro+.

A new strategy is live: two configurable EMAs cross — BUY on the upward cross, SELL on the downward cross. Default 9/21, faster and more tunable than Golden Cross. Plus optional volume- or price-confirmation filter to fight whipsaws.

The Take-Profit / Re-Entry strategy combines two simple rules: sell when your target gain is reached, re-enter when price drops enough from the post-sell high. No indicator noise — just price and two parameters.

We wrote 500 lines of rules. Claude read them — and still wrote text-[13px] instead of text-xs. The mistake wasn't Claude. The mistake was confusing documentation with enforcement.

Grid bots are marketed as "low-risk" and, with AI, as a source of "consistent profits." We checked the claims against the mechanics: a grid earns on sideways oscillation, not trends — and "always trading" means trend-chasing. A fair breakdown, plus how to actually evaluate a grid bot.

High funding rates signal overheated longs — a warning. Negative funding means shorts capitulating — a buy signal. The logic seems solid. We tested it across 6.7 years of BTC data. The results were the opposite of what we expected.

A new strategy is live: John Bollinger's classic volatility-cycle play. Wait for the bands to squeeze tight, then ride the long breakout above the upper band. Default 20/2.0/0.1. Pro+.

Most traders writing their own backtests accidentally look into the future. The result: spectacular backtests, collapsing live performance. A look at the subtlest methodology mistake in systematic trading — from the common `shift(-N)` to the innocuous `.mean()` aggregation without rolling window — and why we manually check every Backtesting Arena strategy for bias before release.