ETFs pegged to gold and Treasury Inflation Protected Securities have delivered the top risk-adjusted returns over the past five years on fears central bank easing would debase currencies, according to a report.

However, investors have been of two minds on these asset classes recently in the wake of the Federal Reserve launching QE3. [Central Banks Will Devalue Currencies, Gold ETF Bulls Say]

For example, investors have been piling into gold ETFs. The largest precious metal ETF, SPDR Gold Shares (NYSEArca: GLD), has raked in $3 billion since the end of August. [Gold ETF Bullion Holdings at Record After $3B Monthly Inflow]

About 191 metric tons of gold have flowed into related ETFs since the end of July, and buying in gold exchange traded products totaled nearly $8 billion in the third quarter, the highest quarterly inflow in over two years, MarketWatch reports. [Gold Rush is On in ETFs]

Conversely, investors have yanked $840 million from iShares Barclays TIPS Bond Fund (NYSEArca: TIP) since the end of August, according to IndexUniverse ETF flow data.

The outflows suggest investors are locking in profits after the TIPS ETF rallied to all-time highs, or see deflation as a greater threat than inflation. Additionally, the recent selling could mean investors are nervous that TIPS could be hurt if interest rates rise. [Deflation Warning? – Investors Dumping TIPS ETFs]

“Gold and TIPS are the most liquid way to get exposure to inflation,” said Michael Mullaney at Fiduciary Trust in a Bloomberg News report Wednesday. “The volatility in gold and TIPs will remain low going forward as the ugly head of inflation will emerge, and we will see a steady increase in gold demand.”