The U.S. dollar closed stronger on major markets yesterday but fell off in New York on false reports of a coup in Saudi Arabia. Gold bounced up and down like a yo-yo in light trading.

Gold fell to $631.50 in Zurich from Tuesday's close of $644.50. In London, however, gold rallied to close at $642.50 an ounce, up from $640.50. In New York, gold fell off again to close at $630 an ounce, almost even with $630.25 Tuesday. The Comex settlement price was $629.50 an ounce. In the late afternoon it was trading at $632 on the curb market.

European closing prices for the dollar, with New York prices in parentheses:

Frankfurt, 1.7628 marks, up from 1.7620 at Tuesday's close (1.7590); Zurich, 1.66895 Swiss francs against 1.6680 (1.6655); Brussels, 29.505 Belgian francs against 29.4050 (28.57); Amsterdam, 1.9430 guilders against 1.9410 (1.9390); Milan, 816.55 lire against 815.20 (816); Paris, 4.13125 francs, down from 4.1332 (4.1250).

In London, the pound rose to $2.2875 from Tuesday's close of $2.2765, and it closed at $2.2870 in New York. In Tokyo, the dollar strengthened fractionally, closing at 248.75 yen against 248.40 at Tuesday's close, but it eased off to 248.18 yen in New York.

The Canadian dollar rose sharply, closing at 87.22 U.S. cents compared with 86.97 Tuesday. New York dealers said the dollar's late weakness was the only factor that could account for the Canadian currency's rise.