Investors pulled nearly $6 billion out of exchange-traded funds in February, the first time ETF fund flows have been negative in nearly a year.

The new data, compiled by the National Stock Exchange and published on Wednesday, reversed the strong trend seen in January 2009 and December 2008. That's when investors poured more than $80 billion into ETFs.

The bulk of the outflows can be laid at the feet of a single fund, the S&P 500 SPDRs (NYSE Arca: SPY), which saw $13.6 billion in net outflows.

That's not unusual, either. Stripping out SPY and another heavily traded fund used by institutional investors, the PowerShares QQQ (Nasdaq: QQQQ), ETFs as a whole have generated 78 straight months of net inflows. 

"Those two are so heavily traded by institutions for so many temporary different reasons -- to replenish cash reserves, tax purposes and as an intermediate way to switch around positions within the same asset classes -- that they're really like outlying funds separate from the other ETFs," said Michael Traynor, the NSX's chief strategy officer.

In February, the QQQ's had net outflow of $724 million. 

"There's no telling what institutions are doing from one month's worth of data. This happens so frequently, however, reading too much into the trading volatility of SPY and QQQQ probably won't lead to many sound conclusions," said Traynor. 

That gigantic move overwhelmed the positive flows into funds like the SPDR Equity Gold ETF (NYSE Arca: GLD), which led all ETFs with $5.6 billion in inflows; GLD closed the month with $31.5 billion in assets. The Market Vectors - Gold Miners (NYSE Arca: GDX was second, with $1.1 billion in inflows, followed by the U.S. Oil Fund (NYSE Arca: USO) at $924 million. Other funds to make the top 10 on inflows were the iShares Barclays TIPS ETF (NYSE Arca: TIP) at $840 million and three leveraged funds: the ProShares Ultra S&P 500 (NYSE Arca: SSO), ProShares Ultra DJ Financials (NYSE Arca: UYG) and the Direxion Financials Bull 3x (NYSE Arca: FAS). The trend of inflows into leveraged bull market ETFs suggest a number of investors positioning themselves for a bottom in these beaten-down markets.

ETFs suffering outflows were led by large established ETFS like the aforementioned SPDRs and the iShares MSCI EAFE ETF (NYSE Arca: EFA). Investors also pulled money out of a handful of inverse ETFs designed to go up when the market goes down.