Recent strength in exchange traded funds that invest in U.S. Treasuries doesn’t bode well for stocks and shows investors worried about deflation are moving into safe havens.

The U.S. government sold debt at a record-low yield last week, as buyers accepted a negative payment for the third time in history on 10-year notes.

“The U.S. is the favorite safe haven,” Hiromasa Nakamura, investor for Mizuho Asset Management Co., a unit of Japan’s largest publicly traded bank, said in a report. “There’s a flight to quality. The world economy is declining. Recently the rally has gained strength.” [Treasury ETFs: TLT Nears All-Time High as Yields Plunge]

The rally in Treasury ETFs reflects concerns that Greece will leave the euro, and also suggests investors are worried about deflation. Investors are reacting to fear as they look for safe havens to park their cash, due to the intensifying Eurozone crisis. Yields have been driven to all-time lows as investors are filing out of stocks and into U.S. government bonds. [Treasury ETFs Rally as 10-Year Yield Dips Below 1.8%]

The iShares Barclays 20+Year Treasury Bond (NYSEArca: TLT) has gained about 10% on the latest rally. News of Greece leaving the Eurozone and weak domestic economic data have investors seeking safety. [ETF Spotlight: Inflation Protection]

“This week, technical indicators such as the relative strength index reached overbought levels. What this means is that the rush into the market, sparked by the recent escalation of problems in Greece, pushed prices too far, too fast,” Michael Kahn for Barron’s wrote.

Although Treasuries have given investors a place to hang out amid Europe’s troubles, when considering trading price or risk, they are not looking attractive, reports Kahn. The problem is that the Treasury market has already reached the price ceiling that stopped it on many occasions over the past year, which has corresponded with historic low yields.

iShares Barclays 20+Year Treasury Bond

Tisha Guerrero contributed to this article.

The opinions and forecasts expressed herein are solely those of Tom Lydon, and may not actually come to pass. Information on this site should not be used or construed as an offer to sell, a solicitation of an offer to buy, or a recommendation for any product.