Foreign Exchange
The largest market on earth, $9.6 trillion a day of one money traded for another: what moves a currency, the dollar system and its 2025-26 test, the majors, the yuan, and the emerging currencies' dollar-debt trap, the machinery of a trade, the interventions, pegs, and crises and who won them, and the hedge and the carry. Written as of October 2026, with the dollar at its highest since April 2025, the euro at its low for the year, and the yen near its weakest since 1986 after two rounds of Japanese intervention, one joined by the United States. Where the field argues, from whether the dollar's dominance is ending and what stablecoins do to it to whether the yuan can become a reserve currency and whether America should weaken the dollar on purpose, each side makes its case before the evidence. Opens with a market snapshot from one day's close, and its four worked examples run on 2026's numbers, from the Fed's September rise through the euro and the yen to Japan's intervention arithmetic, a hedged Treasury for a Japanese insurer, and a manufacturer's hedge.