India's forex reserves jumped by $223 million to hit a fresh all-time high of $689.46 billion for the week ended September 13, the Reserve Bank of India (RBI) on Friday.According to the Weekly Statistical Supplement released by the RBI, Foreign currency assets (FCAs) dipped by $515 million to $603.63 billion. Expressed in dollar terms, the FCAs include the effect of appreciation or depreciation of non-US units like the euro, pound and yen held in the foreign exchange reserves.Gold reserves saw a surge of $899 million to $62.8 billion. Meanwhile, SDRs for the above mentioned week were down by $53 million to stand at $18.42 billion. Reserve position in the IMF dipped by $108 million to $4.52 billion.The RBI, from time to time, intervenes in the market through liquidity management, including through the selling of dollars, with a view to preventing a steep depreciation in the rupee.The RBI closely monitors the foreign exchange markets and intervenes only to maintain orderly market conditions by containing excessive volatility in the exchange rate, without reference to any pre-determined target level or band.