The amount was the biggest since the week of November 4-7, when foreigners bought a net 769 billion yen, which some brokerages that track historical data say is the record. Japanese shares have risen this year on expectations that profits will be pushed up by a weak yen and that consumption will be helped by a slump in oil prices and higher wages. Last week, the Nikkei traded above 20,000 for the first time since April 2000.
"Long-only funds which had been underweight of Japan were seen buying Japanese stocks," said Norihiro Fujito, a senior investment strategist at Mitsubishi UFJ Morgan Stanley Securities.
"They were lagging behind the Japanese markets' rises. When they are buying, they tend to chase such large cap stocks as banks higher."