Let us look at a hypothetical example to understand how the IPO allotment calculation is done in the case of oversubscription.
Assume a company issues 1,000 shares to the public via an IPO, with the minimum lot size at 100 shares. The maximum number of lots that can be issued is 10 (1,000 shares ÷ 100 shares). Now, suppose 20 investors apply for the issue in the following manner:
| Investor | Number of Lots Applied |
|---|
| Investor 1 | 2 |
| Investor 2 | 1 |
| Investor 3 | 4 |
| Investor 4 | 3 |
| Investor 5 | 2 |
| Investor 6 | 5 |
| Investor 7 | 7 |
| Investor 8 | 1 |
| Investor 9 | 3 |
| Investor 10 | 8 |
| Investor 11 | 3 |
| Investor 12 | 4 |
| Investor 13 | 8 |
| Investor 14 | 3 |
| Investor 15 | 2 |
| Investor 16 | 5 |
| Investor 17 | 3 |
| Investor 18 | 4 |
| Investor 19 | 7 |
| Investor 20 | 6 |
Since the issue is oversubscribed and the maximum number of lots is only 10, the registrar opts to make IPO allotment through the computerised lottery system. This system randomly selects 10 investors and allocates one lot each. Here is a hypothetical representation of how the allotment is done:
| Investor | Number of Lots Applied | Number of Lots Allotted |
|---|
| Investor 1 | 2 | 0 |
| Investor 2 | 1 | 1 |
| Investor 3 | 4 | 0 |
| Investor 4 | 3 | 0 |
| Investor 5 | 2 | 1 |
| Investor 6 | 5 | 1 |
| Investor 7 | 7 | 0 |
| Investor 8 | 1 | 0 |
| Investor 9 | 3 | 1 |
| Investor 10 | 8 | 0 |
| Investor 11 | 3 | 1 |
| Investor 12 | 4 | 1 |
| Investor 13 | 8 | 0 |
| Investor 14 | 3 | 0 |
| Investor 15 | 2 | 1 |
| Investor 16 | 5 | 0 |
| Investor 17 | 3 | 0 |
| Investor 18 | 4 | 1 |
| Investor 19 | 7 | 1 |
| Investor 20 | 6 | 1 |
As you can see, through the computerised lottery system only 10 investors were allotted shares. These 10 allotted investors will receive the company's shares in their demat accounts within a few days from the IPO allotment date. For the unallotted investors, however, the blocked application amount is released.