The Indian rupee has been continuously declining against the US dollar for over a month and has lost\u00a0about 229 paise per the USD under the same period into consideration mainly led by the sharp surge in the crude oil prices. Earlier in January this year, the rupee hovered between the range of 63.85 and 63.59 against the US dollar but tripped into losses after the Finance Minister Arun Jaitley tabled the Union Budget 2018. On the Budget day itself, the rupee shed as much as 44 paise per US dollar when Arun Jaitley brought the LTCG (Long-Term Capital Gain) on equities over Rs 1 lakh under the tax net of 10%. Since then, the domestic currency has been broadly plummetting against the US dollar despite a few marginal upticks. Specifically, in the last one month, a steep plunge has been observed in the rupee against US dollar. The Indian rupee has slipped by as much as 229 paise (approx) to 67.28 apiece US dollar from a level of 64.99 as on 10 April 2018. Today only, the rupee extended yesterday's losses to hit a fresh 15-month low. The rupee slipped\u00a0about 14 paise to a new 15-month low of 67.28 against US dollar at the interbank foreign exchange market in the mid-morning deals on Tuesday. The Reserve Bank of India has fixed a reference rate for rupee at 67.1060 per US dollar and 90.8481 against the Great Britain pound, 80.1179 against euro and 61.4400 against Japanese Yen on Monday, 7 May 2018. Earlier yesterday, the rupee dropped 26 paise to close at 67.13 against US dollar. This is the lowest level for the Indian unit since 8 February 2017 when the domestic currency ended at 67.19 against the US dollar.\u00a0The dollar US traded near its a four-month high today followed by the upbeat prospects for the US economy. The US dollar index against a\u00a0basket of six major currencies was 0.1 percent higher at 92.864 after reaching 92.974 overnight, its highest since 28 December 2017, Reuters said in a report. The US dollar has strengthened in the recent past on the back of rising US Treasury yields and solid economic data. According to a Reuters report, diminished market concerns over perceived risks from the US-China trade spat and North Korea, have further helped shift investor focus back on dollar-supportive fundamentals over the past month. We take a look at two biggest reasons for the fall in Indian rupee vs US dollar FPI's exit Foreign portfolio investors (FPIs) investment have been on a cyclical trend since the beginning of this year. In the month of April, FPI outflows hit a 16-month high.\u00a0As per the latest data available with the depositories, FPIs sold Rs 15,558 crore worth of equities and debt securities in April due to the continuous rise in the crude oil prices. The increase in the outflows from Indian capital market can also be attributed to a rise in yields of government securities.\u00a0The heavy outflow was followed by the influx of Rs 11,654 crore in March and an outflow of Rs 11,674 crore in February. Notably, in the month February, volatility across the domestic stock markets escalated up due to global sell-off and LTCG being implemented on equity investment over Rs 1 lakh. The outflow of Rs 15,558 crore from Indian capital markets is at the highest level since December 2016. So far in 2018, FPI's have withdrawn over Rs 14,000 crore in the debt securities while, on the other hand, have bought Rs 7,100 crore worth of equities on a collective basis. With such a sell-off in domestic capital markets, the supply of rupee seemed to have increased resulting in weakening in its strength as against US dollar. Boiling crude oil prices Crude oil prices are hovering near their respective 4-year peaks. Earlier yesterday, Brent Crude and WTI (West Texas Intermediate) crude surpassed the levels of $75 and $70 per barrel, respectively. This would impact all the oil importing economies including India and adversely affect it's CAD (current account deficit), fiscal deficit, imported inflation and create headwinds for economic growth, Ajay Bodke, CEO, Prabhudas Lilladher was seen as saying in a PTI report. Huge purchases of US dollar by oil importing companies along with speculative activity largely weighed on the rupee, PTI reported citing an unidentified currency dealer. Meanwhile today, Crude oil prices dipped a little from their respective 4-year highs as market participants were keenly awaiting the announcement by the US president Donald Trump on reimposition of sanctions on Iran. According to a Reuters report, Donald Trump on Monday said that the decision on whether to remain in the Iran nuclear deal or to impose sanctions would be announced at 1800 GMT on Tuesday, four days earlier than expected. At the time of writing, Brent crude oil was trading down 0.83% at $75.54 per barrel, its\u00a0highest since November 2014 while US WTI crude was trading down 0.95% at $70.06 per barrel on Tuesday. Earlier on Monday, oil prices escalated to highest levels since November 2014 with Brent crude surpassing $75 per barrel mark led by\u00a0Venezuela's economic crisis.