Investors have pulled $18 billion from the SPDR S&P 500 ETF (SPY) this year, more than the $16 billion invested in the fund in all of 2013, despite new highs in U.S. stocks, the Financial Times reported.

The FT said the divergence could be interpreted as a disconnect between the recent stock market highs and investor sentiment.

The SPY ETF, the largest ETF with about $159 billion in assets, seeks to track the performance of the S&P 500 Index, a U.S. benchmark gauge of 500 large stocks. The S&P 500 is up about 1.5% this year.

In afternoon trade, SPY was down 0.33% to $187.63.

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