Sensex & Nifty crash post budget , Investors may be losing sleep over the re-entry of long-term capital gains tax on equities, but analysts feel that the worrylines are actually running deeper than you realise. Top Reasons attributed by Market leaders inclusive :

Doubts in Government Claim on Indirect Tax :

The tax figures being touted by the government, according to brokerages, are a little ambitious. The Budget has projected a 19.1 per cent rise in indirect taxes on likely strong economic growth. whereas Motilal Oswal Financial Services noted that the indirect tax estimate implies a sharp jump in buoyancy to 1.66 in FY19, from 1.14 in FY18, and a 27 per cent growth in monthly run rate of GST collections. The gross taxes too are budgeted to go beyond 12 per cent of GDP for the first time ever it noted.

"A sharp revisions in almost all budget items for FY18 raise doubts over the sanctity of FY19BE numbers. It is also notable that capital spending is budgeted to fall to 1.6 per cent of GDP in FY19BE - the lowest in the past half a century versus 1.8 per cent in FY17," the brokerage said.

William Foster, VP-Sovereign Risk Group at Moody's Investors Service, told ET Now that there are still challenges around GST and the revenue collections have been about 2 per cent of GDP.

"Next year, the (revenue collection) expectations are for about 4 per cent of GDP, which is pretty significant pick- up. There are still challenges around implementation and compliance. That is one area in terms of revenues where there seems to be some uncertainty, moving forward. But obviously over time, we expect GST to really get entrenched in the system and people will be able to comply better. This could be another transitional year towards ultimate stability in the medium term," Foster said.

What is also baffling analysts is the fuel subsidy that has been kept at the FY18 level, even as the overall subsidy on food, fertilisers and petroleum products has been raised by 15 per cent to Rs 2.64 lakh crore. This, at a time when Goldman Sachs has raised its three-month Brent forecast to $75 and its six-month forecast to $82.50 a barrel level, which could blow up Rs 25,000-30,000 crore as slippage, Motilal Oswal Securities said.

Many also are wary of the hike in MSP and its impact on inflation. "The Reserve Bank of India (RBI) will undoubtedly be more hawkish at its meeting on 7 February 2018. Our base case is for a rate hike in Q1 FY19, with an inflation-targeting central bank preferring to pre-empt a surge in inflation," Nirmal Bang Institutional Equities said in a note.

Health Care Scheme Skeptics :
The mega ambitious healthcare scheme announced in the Union Budget on Thursday is one such point of concern which aims to benefit 10 crore poor families for secondary and tertiary care hospitalisation. Sceptics are having a field day, wondering how the government will fund a programme with such a wide canvas.

Foreign brokerage BofA-ML noted that even if 5 per cent of beneficiaries claim half the intended amount, the total cost could swell to a whopping $20 billion an amount the government may not have accounted for in the Budget.