The curious case of IDBI Bank's winner Wednesdays
There’s something about Wednesdays for IDBI Bank investors. Over the past year, the lender’s shares have delivered their strongest average returns midweek, only to lose ground the following day.
A Mint analysis of market data reveals a curious pattern, seemingly driven by investors betting on a breakthrough in the bank’s long-awaited privatization at the Union cabinet’s meetings that are typically held on Wednesdays.
The stock generated an average return of 1.08% on Wednesdays over the last one year, shows the analysis. And Thursdays saw an average return of negative 0.8%, implying traders booked profits in the very next session.
After Wednesday, Fridays brought the highest average return of 0.7%; followed by Tuesdays, where the average return was 0.14%. The lowest average was at negative 0.9% recorded on Mondays.
The Wednesday cheer anomaly becomes even more evident seeing the stock’s biggest single-day gains. Of IDBI Bank's ten largest single-day price spikes over the past year, half or five of them happened on a Wednesday.
The single largest one-day gain occurred on Wednesday, 17 June 2026, when the bank's shares surged 17% at market close.
“Wednesday has recorded higher average trading volume than most other weekdays, but this appears to be driven by a few event-led spikes, rather than a consistent weekday effect," said Hitesh Tailor, technical research analyst at Choice Broking. "Over the last year, Wednesday’s average volume was around 22.28 million shares against an overall average of 17.82 million, approximately 25% higher.”
However, excluding the two exceptional sessions on 17 June and 14 October, Wednesday’s average falls to around 15.3 million shares, below the overall average. And excluding these two spike sessions, the average returns for the day go down to 0.59%.
This indicates trading activity is linked more closely to major announcements and sharp price movements than to a particular day of the week, Tailor added.
This Wednesday, 14 October, the Cabinet Committee on Economic Affairs (CCEA) approved sale of a 60.72% stake in IDBI Bank, held by the government and Life Insurance Corp, to Canada Inc., the parent entity of Fairfax Financial Holdings, for ₹52,878 crore. The stock closed 8.98% higher on 14 October on expectation of a government announcement, which came late evening.
The transaction will trim government’s direct holding to 15% and LIC’s stake to 19%, leaving them with a combined minority shareholding of 34%. The move is part of government’s broader strategy to pare its investments in non-core assets and financial institutions that have previously received bailout support.
And not surprisingly as per the trend, 15 October, a Thursday, saw a sharp decline. Profit booking battered the stock, and it ended 8.1% lower at ₹83.07 on the National Stock Exchange, erasing almost all the gains of the previous session.