The rest of this month is unusually dense. Between 12 and 29 September 2026, Indian markets face two domestic inflation prints, three central bank decisions, the largest initial public offering in Indian history and a monthly derivatives expiry, in that order.
The clustering matters more than any single item. A Federal Reserve decision on 16 September, priced at roughly 90% odds of a hike, lands one day before retail investors are asked to fund a Rs 22,569 crore share sale, which means the same week decides both the cost of global money and the appetite for the biggest domestic issue on record.
The calendar in order
The three that actually move portfolios
The Federal Reserve on 16 September is the largest of them. US CPI came in at 3.4% on 11 September and producer prices at 5.4% the day before, taking hike odds to about 90%, which our US CPI August 2026 piece covers. Because the hike is priced, the risk sits in the statement rather than the decision, and a signal of more tightening would extend the pressure on the rupee and on foreign flows.
The NSE IPO from 17 to 21 September is the largest domestic event. The price band is Rs 1,700 to Rs 1,785 for a pure offer for sale, with a minimum lot of 8 shares at Rs 14,280, allotment on 22 September and listing on 24 September. An issue this size absorbs investor capital that would otherwise sit in the secondary market, and the details including the FY26 profit decline are in our NSE IPO analysis.
India's CPI on 12 September decides the domestic policy story. The repo rate has been at 5.25% since June, and with Brent above $100 the transport and fuel components are the ones to watch, a calculation our will the RBI cut rates piece sets out.
The ones people forget
The Salalah meeting on 14 September is the one that could reprice everything else. Iran sits with Gulf foreign ministers and Iraqi representatives on Hormuz shipping, and Brent already paused near $104 on the announcement, as our Hormuz talks piece covers.
The Bank of Japan on 18 September matters through the carry trade. Japanese tightening raises the cost of yen-funded positions across emerging markets, and an unwind reaches Indian equities without any Indian cause, the mechanism our yen carry trade piece explains.
The CLARITY Act procedural vote on 15 September is binary for crypto. Failure to clear the Senate hurdle could end the bill's chances this year, and the sequence is laid out in our crypto decision week piece.
The advance tax instalment on 15 September removes cash from the system. Corporates and individuals must have paid 45% of the year's estimated liability by that date, which routinely tightens short-term liquidity in the third week of September.
The F&O expiry on 29 September is now on a Tuesday. NSE moved monthly equity derivative expiries to the last Tuesday of the month, so anyone still working off the old last-Thursday convention will get the date wrong, and our open interest and PCR guide covers what expiry week does to positioning.
What to watch inside the calendar
The first is sequencing, not content. The Fed decision lands a day before the NSE issue opens, so a hawkish statement would hit sentiment exactly as retail investors decide how much to bid. The order of events is doing as much work as the events themselves.
The second is liquidity. Advance tax on 15 September, a Rs 22,569 crore IPO from 17 September and refunds returning around 22 September put three separate cash movements inside one week.
The third is oil, which sits under all of it. Brent above $100 after the Strait of Hormuz disruption is feeding the inflation prints on both sides of the world, a link covered in our Brent crosses $100 note, and a ceasefire would change every item on this list at once.
The fourth is the festive quarter starting underneath. Consumer demand through the Diwali cycle is what the earnings season in October will be priced on, and the broader month is framed in our stock market September 2026 outlook.
Risks to monitor
The second risk is the IPO itself. A large offer for sale pulls money from the secondary market and can weigh on the index during the subscription window, and a weak listing on 24 September would affect sentiment for the rest of the pipeline.
The third is the data that is not scheduled. The Gulf conflict has produced unscheduled moves all quarter, and nothing on this calendar prevents another one. This is general information, not investment advice.
The useful habit with a month like this is not predicting each outcome. It is knowing which dates deserve attention, so that a 400-point move on 16 September reads as a scheduled event rather than a surprise.