Why market is down today: Sensex falls 800 pts, Nifty tests 23,800; here are 5 reasons 

Benchmark indices Sensex and Nifty plunged over 1 per cent each in Wednesday’s trade, tracking a sell-off across Asian markets as Brent crude oil prices rose for the third straight day following fresh US attacks on Iran. US President Donald Trump also signalled no desire to engage with Iran.

Market sentiment was further hit by rising US bond yields, with the 10-year Treasury yield touching 4.80 per cent, raising concerns over inflation and keeping pressure on emerging-market assets.

Sensex fell 808 points or 1.05 per cent to hit a low of 76,135.72. Nifty briefly declined below 23,800 to a low of 23,786.80. It was later trading at 23,827, still down 219.90 points or 0.91 per cent.   Eternal Ltd, Infosys Ltd, HCL Technologies Ltd and UltraTech Cement led Sensex's losers, falling up to 1.8 per cent. A total of 28 of 30 index constituents fell. On the other hand, 46 of 50 Nifty index stocks fell, with Shriram Finance, down 2.62 per cent, falling the most.

Escalation in US-Iran war
"The escalation of the US-Iran conflict and the consequent 5 per cent spurt in Brent crude overnight to $96 a barrel is a sentiment negative. However, this is not a big threat since our CAD is running at only 0.5 per cent and forex reserves are ample at $730 billion," said V K Vijayakumar, Chief Investment Strategist, Geojit Investments.

Rising US bond yields
The bigger threat is the rising bond yields in the US. The macro construct in the US indicated further hardening of the bond yields. Data showed yields in Japan and the UK. also pushed toward multi-decade highs, while the 30-year Treasury yield hovered near a two-decade high. In Europe, annual inflation rose to 3.3 per cent, adding to pressure on the ECB.

"If the 10-year US yield touches 5 per cent that has the potential to trigger a big correction in equity markets globally. Therefore, this is the macro indicator to watch closely. The near-term market trend will depend on which of these forces -the tailwinds or headwinds- will emerge stronger," Vijayakumar said.

Asian markets take hit 
Asian market fell on increasing oil prices, rising US bond yields and flaring up of US-Iran war. Korea's Kospi was worst-hit with 3.84 per cent drop. Japan's Nikkei 225 fell 2.81 per cent. It was followed by 1.25 per cent fall in Hong Kong's Hang Seng. China's Shanghai Composite also slipped 0.82 per cent. US indices such as Dow Jones, S&P500 and Nasdaq Composite also had settled up to 1 per cent lower overnight.

Energy prices, inflation
Devarsh Vakil, Head of Prime Research at HDFC Securities said rising energy costs are stoking fears of sticky inflation, adding pressure to borrowing costs and weighing on richly valued equities — complicating the Fed's next policy move.

Trump in no mood to engage Iran
In a post on Truth Social, the US President Donald Trump  said he was not seeking to force Iran to the bargaining table.

Instead, he said: "I couldn’t care less if they sign a worthless, to them, agreement. I like our position now much better, with almost total control of the Hormuz Strait, and their economy totally collapsing. They are just playing out the inevitable. When are the Iranian people going to rise up and fight?."