IPO allotment: how an oversubscribed issue picks who gets shares

What is an IPO allotment?

Allotment is the step between bidding and listing, when the registrar of the issue works out how many shares each applicant receives. Bids come in during the open window, the issue closes, and only then does anyone learn whether they hold shares.

The registrar finalises the basis of allotment with the stock exchange. The rule that governs it depends on how many bids arrived against how many shares were offered. If the total demand is below the shares on offer, every valid bid is filled in full. If demand is higher, the issue is oversubscribed and a rationing rule takes over.

How does an oversubscribed issue pick who gets shares?

The shares are split into separate books before bidding opens, and each book rations in its own way. The three books are institutions, large non-institutional bidders and individuals bidding up to ₹2 lakh. As of 19 October 2026, Groww's note on the Jio Platforms issue gives the split of the net issue. Qualified institutional buyers get not more than 50 percent, non-institutional investors not less than 35 percent and individual investors not less than 15 percent.

The individual-investor book

This book is rationed by lot, and the lot is the unit that matters. When there are more applicants than lots to hand out, a computerised draw picks the winners, and a winning application receives one lot.

Western Carriers' basis of allotment, hosted on the National Stock Exchange of India's site, shows the result. The book was subscribed 27.21 times. It received 2,560,721 applications and allotted shares to 115,282 successful bidders. The lot was 87 shares.

The non-institutional book

Bids above ₹2 lakh go into a separate book, which the notice rations in proportion to bid size, with a ratio for each size band. In the same notice, the band from ₹2 lakh to ₹10 lakh was subscribed 56.89 times, against 27.21 times for the individual book. Both numbers come from one issue and one notice, so each book has its own multiple and its own odds.

The institutional book

Qualified institutional buyers bid through their own book, and it rations proportionately to bid size. The notice records that book subscribed 28.53 times, and that mutual funds were allotted 5 percent of it as the rules require. The QIB book is also the one that usually fills last.

Source: Western Carriers (India) Limited basis of allotment notice, nsearchives.nseindia.com, read on 19 October 2026. Groww, "Jio Platforms IPO to Open on October 21, 2026", groww.in, read on 19 October 2026.

Does a bigger bid improve your odds of getting shares?

No, once the individual book has more applicants than lots. The draw counts applications, not rupees. A bid for 13 lots is one application, one entry in the draw, and if it wins it receives one lot.

The Western Carriers notice puts numbers on it. A bid at the offer price of ₹172 per share for one lot of 87 shares cost ₹14,964 (87 × 172). A bid for 13 lots, 1,131 shares, cost ₹1,94,532 (1,131 × 172). The notice lists 2,355,074 applications for one lot and 13,771 for 13 lots. Every bid size from 1 to 13 lots carried the same ratio, 19 in 422, which is 4.5 percent (19 ÷ 422 = 0.045).

Each winner in every size band received 87 shares. The notice closes the book with a single spare share, awarded by a 1 in 9,258 draw among winners from the multi-lot bands. The 13-lot bidder committed ₹1,79,568 more (₹1,94,532 − ₹14,964) for the same 4.5 percent chance of the same 87 shares.

The lots on offer were 115,282 (10,029,535 ÷ 87), against 2,560,721 applications. Applications outnumbered lots by more than 22 to 1, so the extra lots on a 13-lot bid had nowhere to go.

Source: Western Carriers (India) Limited basis of allotment notice, nsearchives.nseindia.com, read on 19 October 2026.

Why the subscription multiple misleads about your own odds

A subscription multiple of 27.21 suggests odds of about 3.7 percent (1 ÷ 27.21 = 0.0367). The actual share of applicants who received shares was 115,282 out of 2,560,721, which is 4.5 percent.

The two differ because the multiple counts shares applied for, and many applicants bid for several lots. A 13-lot bid raises the multiple by 13 times as much as a one-lot bid and adds one entry to the draw. The multiple therefore measures how much money turned up. Your odds depend on how many applications turned up, and the final basis of allotment prints that count.

That is also why the grey market premium answers a different question. The grey market premium is an unofficial quote on where the shares might trade after listing. It carries no information about whether your application is drawn.

What does a larger bid cost while you wait?

The bid amount stays blocked in your bank account, through the UPI mandate or ASBA, until allotment is final. Western Carriers' notice describes the bid amount as blocked by the bank in both routes.

Take the Jio Platforms issue as the dated example. As of 19 October 2026, ThePrint's PTI report gives a price band of ₹1,065 to ₹1,119, a lot of 12 shares, and ₹13,428 for one lot at the cap price. Groww's note lists the maximum individual bid at 14 lots, 168 shares, ₹1,87,992.

The difference between the two bids is ₹1,74,564 (₹1,87,992 − ₹13,428). On Groww's tentative schedule, bidding runs from 21 to 23 October 2026, the basis of allotment is finalised on 26 October and refunds start on 27 October. A bidder who goes for 14 lots keeps ₹1,87,992 out of reach for that whole window. If the book is oversubscribed in the way Western Carriers was, the 14-lot bidder faces the same draw as the one-lot bidder.

Whether Jio's individual book is oversubscribed will be known only when bidding closes, and nothing here forecasts it. If it is, the draw works as described above.

Source: ThePrint (PTI), "Jio Platforms sets IPO price band at Rs 1,065-1,119, targets to raise record Rs 30,213 cr", 14 October 2026, read on 19 October 2026. Groww, "Jio Platforms IPO to Open on October 21, 2026", read on 19 October 2026. Dates on Groww's schedule are tentative.

What should you do with this before applying?

Size your application by what you can leave blocked in your account. In an oversubscribed book, one lot is the whole prize, so every rupee blocked beyond one lot buys the same draw and nothing more.

Then read the numbers that exist after the book closes: the subscription multiple for your category and the count of applications behind it. They tell you what the draw was. The first-day price and the lock-in period come after allotment. An offer for sale changes where the proceeds go, and the draw runs the same way.

A draw for one lot is a thin basis for a position. A Crypto SIP buys into the asset on that schedule, so nothing waits on a draw. QSI Growth, Qatobit's flagship Crypto Index, holds Bitcoin, Ethereum, Solana, Gold and a stable reserve and is rebalanced monthly on a published methodology. You can invest in QSI Growth or start a Bitcoin SIP, and the amount you choose is the amount invested.

Frequently asked questions

How is IPO allotment decided when the issue is oversubscribed?

Each book rations on its own rule. In the individual-investor book, a computerised draw gives one lot each to the winning applications. Institutional and large non-institutional books ration proportionately to bid size.

Does applying for more lots increase the chance of allotment?

Not in a book far past full subscription. Western Carriers' individual book, subscribed 27.21 times, allotted every size band from 1 to 13 lots at the same 19 in 422 ratio, and each winner received 87 shares.

What is a lot in an IPO?

A lot is the minimum bid, a fixed number of shares you must bid for and then in multiples of. Jio Platforms' lot is 12 shares, or ₹13,428 at the cap price of ₹1,119, as of 19 October 2026.

When is the money released if I am not allotted shares?

The blocked bid amount is released after the basis of allotment is finalised. Groww's tentative schedule for the Jio Platforms issue puts refund initiation on 27 October 2026, and the schedule may be revised.

Does the grey market premium change my allotment chance?

No. The draw runs on applications and lots. The grey market premium is an unofficial price quote and carries no information about whether your application is picked.

Crypto investments are subject to market risk. Not financial advice.