Undersubscription means bids did not cover the shares on offer in the category you are looking at, or in the issue as a whole. The multiple prints below 1×. After a year of loud oversubscriptions, a number like 0.4× looks like a broken page. It is usually a clear page. The market declined the price, the story, or the timing. What happens next depends on whether the issue still clears the minimum subscription the prospectus requires, and on which book was quiet.
A soft category is not a failed issue
Retail at 0.6× with QIB heavily covered is a weak retail response inside an issue that institutions accepted. If the offer still meets its minimum, it proceeds. Retail applicants who bid validly are likely to receive the shares they asked for, because there is no shortage to ration. That is an allotment fact. It is not a verdict that the shares are cheap. Institutions can be wrong, and retail can be right to be cautious, or the reverse. You learn the shape of the book from the subscription tracker. You learn the business from the prospectus.
NII can be the soft book while retail is full, or the other way around. Read the column you would actually enter. A total just above 1× can hide a category that did not cover. Categories are the map. The headline “fully subscribed” is too coarse for this situation.
When the whole offer fails
The prospectus states a minimum subscription, commonly 90% of the offer, below which the issue is not allowed to limp forward with a mostly empty book. If bids do not reach that floor, the offer is withdrawn. Allotment does not happen. Listing does not happen. Blocked funds are released. Your UPI mandate should return to available balance through the same operational path as an ordinary non-allotment, on the timetable the bankers announce for the withdrawal. Mandates and refunds applies here too. You have not “lost the IPO”. There is no IPO.
Underwriting, if the document describes it, can require underwriters to take up a shortfall. That is their contract with the offer, and it is disclosed. It is not a personal promise to you about the listing price, because a withdrawn issue does not list, and a rescued book is still a book the public did not want in full. Read the underwriting section if you want the mechanism. Do not invent a safety net the prospectus does not contain.
QIB portions in book-built mainboard issues have their own expectations of being taken up. If the institutional book is the one that fails, the offer is in trouble even if retail was curious. Retail enthusiasm cannot, by itself, repair an institutional book the structure required. The final file after the close is the one that counts, not the hopeful midday number.
A weak book is not a discount coupon
It is tempting to treat 0.5× as a sale. Sometimes the band was ambitious and the business is fine. Sometimes the business has a problem the unofficial market and the institutions both noticed. GMP in these cases is often negative or absent, which agrees with the subscription file and still does not diagnose the cause. The cause is in the risk factors, the objects, the timing of a market selloff, or a valuation that only worked if every issue that month flew. Book building tells you the price was chosen by the sellers before this evidence arrived. A failed book is the evidence talking back.
Bargain hunters who apply on the last hour of a dying issue are still blocking real money, still dependent on the offer going through, and still exposed to a listing if it scrapes over the minimum. A listing that barely cleared can be a heavy listing. There is no rule that a weak primary book produces a strong secondary price. There is not a rule of the opposite either. You are back at the document.
How to behave as an applicant
If you already applied and the file looks soft, you do not need to “fix” anything for allotment chances. A valid bid in an undersubscribed retail book is already in a good position to receive shares, if the issue proceeds. Withdrawing because you are embarrassed by the multiple is a mood decision. Withdrawing because you have re-read a risk factor is a research decision. Only the second one improves your process.
If you have not applied, a soft file is a reason to slow down, not a reason to heroically support the issue. You do not have a duty to the company. Check whether the minimum is likely to be met. Check whether you still want the shares at the cap if they list poorly. If either answer is uncomfortable, skip. There will be another window. The timeline shows how often these windows actually open.
What this site shows
Below-1× rows are allowed to look like below-1× rows. We do not hide them to keep the homepage cheerful. Empty rows are different: empty means we do not have a file yet. A printed 0.40 is a file. Use it, with the disclaimer, as a description of demand. Then use the prospectus as the description of the company. One without the other is how soft issues become either false bargains or false warnings. They are allowed to be ordinary disappointments, which is what most undersubscribed offers are.