filing
TOKYO, Feb 28 (Reuters) - Hong Kong-based activist fund Oasis Management has bought a 5.08% stake in Japanese online brokerage Monex Group Inc 8698.T , a regulatory filing showed on Monday. (Reporting by Makiko Yamazaki; Editing by Kim Coghill) ((Makiko.Yamazaki@thomsonreuters.com; +81-3-4563-2805;))