Hiroshi Mikitani, founder of Japanese e-commerce empire Rakuten Group Inc., is keeping investors on hold while his own fortune declines.

Once ranked the 25th richest person in Asia, Mikitani no longer even features in the top 140, according to the Bloomberg Billionaires Index. It’s not hard to see why: Rakuten shares are trading near levels last seen in 2010 as investors sour on attempts to grow itself into Japan’s fourth-biggest mobile carrier. That business lost ¥124 billion ($848 million) last quarter alone, an 18th consecutive period of red ink that has ballooned to a total of nearly ¥1 trillion as the firm builds out its mobile operations.

Investors’ patience with the plan has been waning for months. Earlier this year, Rakuten blinked first when it abandoned its "zero yen” data offering, which gave users effectively free bills and was its chief differentiator in a crowded market. Shares have fallen more than 20% since, leaving Mikitani’s $2.7 billion fortune at less than a quarter of its 2015 peak.