Thomas Carlson's Orthogonal Alpha is a core-satellite model built around BTAL, the market-neutral anti-beta ETF (long low-beta, short high-beta equities). BTAL behaves largely independently of the broad market and tends to spike during equity stress, which makes it useful both as ballast and as a timing signal.

The core (50%) holds 2x Nasdaq-100 (QLD) and BTAL in equal weight: QLD supplies upside skew while BTAL supplies crisis convexity, so the pair is smoother than QLD alone. The satellite (50%) is a momentum switch that uses BTAL's own strength as the risk gauge: if BTAL's 1/3/6/12-month momentum beats T-bills it holds BTAL, otherwise QLD. Because anti-beta strength tends to lead equity drawdowns, the model de-risks before the damage.