In early February 2011 BI announced further measures to reduce the risk of exchange-rate volatility in the face of surging inflows of foreign portfolio capital. The central bank revealed that it would end monthly auctions of its six-month BI certificates (SBIs), meaning that nine-month certificates will now be the shortest maturity now sold through auction. The auction of six-month SBIs will be replaced with a six-month term deposit, in line with BI's policy of using term deposits to replace SBIs as the primary instrument for absorbing excess liquidity from the financial system. Term deposits are non-tradable and must be held to maturity, reducing the potential for volatility through secondary-market sales. BI had previously introduced a 28-day minimum holding period for SBIs in June 2010, discouraging investors from investing in such instruments. Sales of three-month certificates were halted in November 2010, and one- and two-month term deposits were introduced at the start of 2011.