On Budget Saturday — a special NSE session — the Nifty fell 3.26%, the biggest budget-day move in ten years. But it was not the budget. That was the day COVID spread beyond China to seven more countries, and global panic set in. A finance blogger had written two days earlier: 'When everyone is thinking of budget, I am thinking of coronavirus.'

The moment the pandemic quietly began for Dalal Street, disguised as a budget crash.

On 13 March 2020 the Nifty hit its first-ever lower circuit. On 24 March it bottomed at 7,511 — a fall of roughly 40% from near 12,400 in a single month, with India VIX exploding from about 15 to 85. The cruel irony: India had almost no deaths at the time. The market was pricing six months of future damage. FIIs sold for 18 straight sessions, about ₹65,000 crore in March alone.

It was the fastest 40% crash in Nifty history, the lowest level the index would ever again see — and the starting point of the greatest bull run in Indian history.

With storage full and delivery physically impossible, WTI crude futures traded at -$37 a barrel — the first time in history oil has gone negative. Sellers were paying buyers to take the oil away. The shock dragged Indian markets lower for two days.

An 'impossible things happen' interlude in the pandemic chapter — and a vivid reminder that fear can invert even the most basic commodity price.

Franklin Templeton wound up six debt mutual-fund schemes — about ₹30,000 crore — amid redemption pressure. The hidden consequence was a butterfly effect: thousands of options sellers had pledged those debt funds as trading collateral. When the exchange set that collateral's value to zero, they were forced to liquidate positions, and the equity market fell sharply on a Friday.

A debt-fund crisis crashed the equity derivatives market through the collateral chain — the most obscure, and most illuminating, 'why did the market fall today?' answer in the dataset.

The UK announced a new COVID variant over the weekend. On Monday, an NSE technical glitch amplified the fall: the Nifty fell 500+ points and Bank Nifty 1,500 points intraday — while UK markets fell just 1.5%. PR Sundar called it a knee-jerk aberration, and the market recovered in three days.

A ~3–4% single-session crash driven more by infrastructure failure than fundamentals — and a preview of the February 2021 NSE outage.

After repeated tech outages, the RBI barred HDFC Bank from issuing new credit cards and launching digital products. India's largest private bank underperformed its peers for years afterwards — a permanent drag on Bank Nifty until the ban was partially lifted in August 2021.

The cleanest 'regulator vs heavyweight = index drag' case study in the dataset.

From the 7,511 low, the Nifty recovered through 10,800, crossed its 200-day average, and rallied to 18,600 by late 2021 — more than a doubling, with barely a 10% correction for most of the run. It crossed 15,000 on 5 February 2021, doubling from the COVID low in under a year.

The same span saw Facebook invest ₹45,000 crore in Jio in April 2020, with Reliance up 10% in a day and on a path to becoming debt-free. It was the greatest bull run in Indian history — and the making of a generation of 'COVID investors.'