A green shoe option is a regulated price-stabilisation mechanism used after an IPO. Calling it an investor “safety net” is misleading because it can moderate disorderly selling, not eliminate market risk.
Step one: over-allotment
Before the offer, a stabilising agent arranges to borrow shares from promoters or pre-issue shareholders. The issue can then allot up to 15% more shares than the base issue size. Cash received for the over-allotment is placed in a dedicated account.
Step two: post-listing purchases
If the market price trades weakly, the stabilising agent may buy shares in the market. Those purchases can support demand and the acquired shares are returned to the lenders. If shares cannot be fully bought back under the mechanism, the issuer may allot shares to cover the balance according to the disclosed arrangement.
What the mechanism does not do
It does not promise that the stock will remain above the issue price. It is time-bound, limited in size and optional. Fundamental news, valuation and market conditions can overwhelm the available stabilisation capacity.
What to read in the prospectus
Check whether a green shoe exists, the stabilising agent, maximum over-allotment, stabilisation period and share-borrowing arrangement. Never assume every IPO contains one.
The bottom line: A green shoe improves the mechanics of price discovery; it does not transform an expensive or weak issue into a safe investment.
Data references: SEBI ICDR price-stabilisation provisions; NISM securities-market investor education material.