premise: On the markets at 9:50 a.m. (ET): In Toronto, the S&P/TSX composite index was down 22.63 points to 16,421.76. The Dow Jones industrial average was up 53.54 points to 26,103.18. The Standard & Poor’s 500 index was up 5.24 points to 2,901.98. The Nasdaq composite index was up 19.76 points to 8037.66. The Canadian dollar was trading at 77.50 cents U-S.
hypothesis: The US dollar was trading 77.50 cents in Canadian dollars
reason: The context explains how 1 Canadian dollar was 77.50 cents of a US dollar, not that 1 US dollar was 77.50 cents in Canadian Dollars.