According to @KobeissiLetter, prediction market Kalshi has surpassed $1 billion in monthly trading volume, with the milestone referenced to Kalshi’s own announcement on X (source: The Kobeissi Letter via X, Sep 15, 2025; Kalshi via X). The cited posts disclose a monthly total but provide no product-level or historical breakdowns, limiting further quantitative comparison from the source material (source: The Kobeissi Letter via X; Kalshi via X). The $1 billion monthly figure provides a stated liquidity benchmark for sizing and routing trades on the venue as reported (source: Kalshi via X; The Kobeissi Letter via X).