Political uncertainty mounted pressure on dollar buying as the US currency crossed the figure of Rs100 after four months on Wednesday.
The dollar was traded as high as Rs100.10 in the inter-bank market while its closing rate was Rs99.95.
The dollar had been trading below Rs100 since March. The open market also crossed the figure of Rs100.
On Monday, the dollar breached the red-line of Rs99 after 40 days, shocking the market.
The currency dealers argued that this was due to large payment of $147 million to IMF and about $100m for oil import.
Since the price was increasing, banks were avoiding selling their holdings depriving importers to make payments against their orders from abroad.
The dollar gained 65 to 70 paisa on Wednesday which was very high for the currency dealers to absorb this shock.