Treasurys yields fell for the third-consecutive session Tuesday, sending the 30-year Treasury yield to its lowest level since May 2013, as a global selloff in equities sparked a flight to less risky assets like U.S. sovereign debt.

In other Treasury trading, the 30-year bond yield (30_YEAR) was down 4.9 basis points to 2.851. Treasury yields fall as prices rise.

The flight to safety started during the Asia trading day after Beijing took fresh steps to rein in growing risks in the country’s debt-laden financial system by banning the use of low-grade corporate debt as collateral to borrow cash, causing investors in China to sell off assets across classes to raise cash in order to comply with the new rules.

The Treasury buying accelerated after the Greek government said it would hold presidential elections on Dec. 17, two months earlier than expected, causing the Greek stock market to suffer its worst-ever collapse.

Investors feared that a victory by Greece’s left-wing anti-austerity Syriza party, led by Alexis Tsipras, could threaten its bailout agreement with the troika of international lenders — the International Monetary Fund, European Commission and European Central Bank.

The 10-year note yield (10_YEAR) fell 5.1 basis points to 2.206%, its lowest level since Nov. 28, while the German 10-year bund yield fell 3.3 basis points to 0.689%, a fresh record low.

Tom di Galoma, head of rates and credit trading at ED & F Man Capital Markets, said that Treasury prices have plenty of room to rise, as investors across Europe, the U.S. and Asia are buying.