DUBLIN, Ireland, June 17, 2013 (GLOBE NEWSWIRE) -- Prothena Corporation plc (Nasdaq:PRTA), a clinical stage biotechnology company focused on the discovery and development of novel antibodies for the potential treatment of a broad range of diseases, announced that the trading of its ordinary shares will be included in the Russell Global Index when Russell Investments reconstitutes its comprehensive set of U.S. and global equity indexes on June 28, 2013, according to a preliminary list of additions posted June 14, 2013 on www.russell.com/indexes . Membership in the Russell Global Index, which remains in place for one year, means automatic inclusion in the appropriate large-cap, small-cap, all-cap indexes as well as the applicable style, sector and country indexes. Russell determines membership for its equity indexes primarily by objective, market-capitalization rankings and style attributes. "We are very pleased to join the Russell Global Index" said Dale Schenk, PhD, President and Chief Executive Officer of Prothena. "It is well established that investors rely on the Russell Indexes for true market representation and we expect our inclusion to have many benefits, including increased liquidity and broader exposure to institutional investors." Russell indexes are widely used by investment managers and institutional investors for index funds and as benchmarks for both passive and active investment strategies. According to Russell, approximately $4.1 trillion in assets currently are benchmarked to Russell indexes. The Russell Global Index, which Russell estimates captures approximately 98% of investable securities globally, is reconstituted annually and all sub-indexes are recalibrated to accurately measure current market realities for each market segment. These investment tools originated from Russell's multi-manager investment business in the early 1980s when the company saw the need for a more objective, market-driven set of benchmarks in order to evaluate outside investment managers. Russell launched the Russell Global Index in 2007, leveraging the popular methodology from its U.S. indexes. The broad-market Russell 3000 ® Index serves as the U.S. component to the Russell Global Index. Total returns data for the Russell Global Index and other Russell Indexes is available at http://www.russell.com/indexes/data/Global_Equity/Russell_Global_returns.asp. About Russell Russell Investments (Russell) is a global asset manager and one of only a few firms that offers actively managed multi-asset portfolios and services that include advice, investments and implementation. Russell stands with institutional investors, financial advisors and individuals working with their advisors—using the firm's core capabilities that extend across capital market insights, manager research, portfolio construction, portfolio implementation and indexes to help each achieve their desired investment outcomes.