ECM Ch.5 — Book-Building & Pricing: Demand Curve and Greenshoe Mechanics
IPO book-building fundamentally differs from DCM — demand is gathered before the price is set. 'Where to cut' the demand curve is the banker's core skill. Greenshoe in three steps: over-allotment → stabilization window → option exercise or market purchase. Why a 15–20% first-day pop is ideal, why a 30% pop is actually a failure, and Korea's mandatory lock-up commitment mechanism.
Ch.1
Why Book-Building Fundamentally Differs from DCM
DCM book-building and IPO book-building share a name but are structurally very different. In DCM, the coupon and maturity are fixed first, and then the spread (price) is narrowed. In an IPO, only a price band is presented initially — investor demand is collected first, the resulting demand curve is analyzed, and only then is the final IPO price determined.
This difference creates a core tension: in an IPO, the issuer wants the highest possible price, investors (especially institutions) want a lower price with a Day 1 pop, and the underwriter must satisfy both sides to maintain long-term relationships. This triangular tension is the politics of IPO pricing.
DCM Book-Building vs IPO Book-Building — Comparison
| Category | DCM | IPO |
|---|---|---|
| Pricing order | Structure → narrow spread | Collect demand → set price |
| Investor info | S&T channels + investor DB | Roadshow + mgmt meetings required |
| Order type | Amount + spread | Shares + price (4 types) |
| Timeline | 1–3 days (IG), 1 wk (HY) | 2–3 weeks (incl. roadshow) |
| Key risk | Rate moves, market volatility | Mispricing, regulatory, market timing |
Ch.2
Demand Curve — Where You 'Cut' Is the IPO Price
Once the bookbuilding period ends, the bookrunner maps the demand curve from the order book. The vertical axis is price and the horizontal axis is cumulative orders at each price level. Since more investors participate at lower prices, the demand curve slopes downward and to the right — exactly like a demand curve in an economics textbook.
However, the actual IPO price decision is not simply about maximizing the oversubscription multiple. The bookrunner simultaneously considers order quality — the proportion of Strike orders, the weight of long-term investors, and lock-up commitment rates. Even with 100x oversubscription, if most orders are short-term speculative orders, the IPO price may be set lower.
IPO Demand Curve — Cumulative Orders by Price (Example)
Core principle: where you 'cut' the demand curve is the IPO price. Cutting at $32 yields 2x oversubscription — going higher means rejecting more investors. The bookrunner considers order quality (prioritizing long-term investors) in making the final pricing decision.
Ch.3
4 Order Types — Signals the Bookrunner Reads
Not all orders are equal. The bookrunner analyzes order types to gauge the true strength and quality of demand. A Strike order signals conviction — 'I'll participate at any price.' A Limit order is conditional — 'only if priced at or below this level.'
Strike Order
Any priceAn unconditional order at whatever the IPO price turns out to be. Most valuable signal to the bookrunner — indicates high-quality demand.
Key investors: Long-only institutions, Pensions
Limit Order
Price capOrder conditional on pricing below a specified level. E.g. '2M shares if priced ≤ $34.' Auto-cancelled if IPO prices above the limit.
Key investors: Price-sensitive institutions, hedge funds
Step-down Order
Volume scales with priceVolume decreases as price increases. E.g. '$30→2M shares, $32→1.5M, $34→1M.' Naturally shapes the demand curve.
Key investors: Large asset managers
Conditional Order
ConditionalValid only if specific conditions are met. E.g. 'Participate only if total book exceeds 3x coverage.' Also used as demand pressure signal.
Key investors: Opportunistic investors, some HFs
Allocation strategy: Order type + quality of investor relationship + lock-up commitment → bookrunner decides allocation. Long-term investors who submit Strike orders tend to receive larger allocations. From the investor's perspective, consistently submitting Strike orders builds the relationship and creates expectations of preferential allocation in future deals.
Ch.4
Greenshoe Option — 3-Stage Mechanism
The greenshoe (over-allotment option) is a mechanism designed to stabilize the stock price immediately after an IPO. The name comes from Green Shoe Manufacturing Company, the first U.S. firm to apply it (1963). It is now standard in most global IPOs.
The core principle is that the underwriter allocates 15% more shares than the offering size to investors (over-allotment), then covers the position based on market conditions — either by buying in the open market (price support when falling) or by acquiring additional shares from the issuer (position close-out when rising).
Issuer grants underwriter an option to issue 15% additional shares. Underwriter allocates 115% of base shares to investors at the IPO price.
→ Underwriter: 15% over-allotment = short position
If price > IPO: exercise greenshoe → acquire additional shares from issuer → deliver to market (profit + cover short). If price < IPO: buy shares in market → price support (stabilization function).
→ Price stabilization + underwriter position closed
Rising price: option exercised → issuer raises additional capital (up to 15% more). Falling price: market purchases cover the short → no additional shares issued, minor underwriter loss.
→ Risk buffer for issuer, investors, and underwriter
Greenshoe's asymmetric design: Stock rises → issuer raises more capital. Stock falls → underwriter buys in market to support price (no additional shares from issuer). Aligned incentives for all parties with no conflict.
Ch.5
Korea-Specific — Lock-up Commitments Determine IPO Price
Korean IPO book-building has a unique mechanism absent from global markets: a preferential allocation system based on lock-up commitments. When institutional investors commit during the demand forecast period not to sell their shares for a certain period, they receive larger allocations proportional to the length of that commitment.
This system serves two functions. First, it removes selling pressure (overhang) during the early post-listing period from the issuer's perspective. Second, from the bookrunner's perspective, higher lock-up commitment rates provide justification for pricing at the top of the band — LG Energy Solution's 67% commitment rate leading to pricing at the band top is the prime example.
Korean IPO — Allocation Upweight by Lock-up Commitment
Real Case: LG Energy Solution (2022)
67% lock-up commitment rate → IPO price confirmed at band top (₩300,000). Institutional demand ratio 2,023:1. Higher lock-up commitments give the bookrunner justification to price higher — because they pre-neutralize the D+180 supply bomb risk.
Korea-specific rules: 50% of the public offering is distributed on an equal-allotment basis (equal opportunity for individual investors), and 50% on a proportional basis (proportional to subscription amounts). Institutions receive 55–75% of the offering through a separate demand forecast period (3 days). Lock-up commitment rates during the demand forecast period are the key variable in determining the final IPO price.
Ch.6
IPO Pop Analysis — Day One Performance Tells Everything
The Day 1 stock price change ('pop') is the key metric for measuring the accuracy of IPO pricing. The closer the pop is to zero, the more favorable for the issuer; the larger the pop, the more favorable for investors. The bookrunner targets somewhere in between.
"A 15–20% Day 1 pop is ideal. Under 5% and the issuer is happy but investors don't come back for the next deal. Over 30% and you've just given money to investors."
— Anonymous ECM Senior Banker
IPO Day-1 Pop Analysis — Issuer vs Investor Perspective
Day 1 < -10%
Officially recorded as failed. Follow-on becomes difficult.
Lyft 2019, Uber 2019 첫날
Day 1 0–10%
Properly priced. Optimal for issuer.
NVIDIA 1999, Google 2004
Day 1 10–25%
Investor satisfaction + modest leave-money. Balanced.
평균 IPO (historical avg ~18%)
Day 1 30%+
Issuer sold too cheap. Investor short-term gain = issuer long-term loss.
Rivian +121%, Snap +44%→이후 폭락
"Leave Money on the Table" Debate
A large IPO pop means the issuer sold too cheaply — the gain accrues to investors (primarily institutional). Research shows the average Day 1 pop for U.S. IPOs is about 18%, representing tens of billions of dollars in annual 'leave money' from the issuer's perspective. However, from the underwriter's viewpoint, a 'reasonable pop' is necessary to maintain investor relationships.
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Frequently Asked Questions
Key Terms
A chart aggregating investor demand by price level. Unlike DCM, IPO book-building collects orders without a fixed price. The x-axis represents the offer price and the y-axis represents shares demanded. The offer price is set at the level where demand fully covers the offering — if oversubscribed at the top of the range, the price is raised; if undersubscribed at the bottom, the price is lowered or the deal is pulled. This is the central output of the book-building process.
An IPO stabilization mechanism in which 115% of the offering size is allocated to investors (15% over-allotment), followed by a 30-day stabilization window after listing. If the stock falls below the offer price, the stabilization agent buys in the market to support the price (covering the short position). If the stock rises above the offer price, the option is exercised with the issuer to receive additional shares. It provides a two-way safety net regardless of stock price direction.
The percentage gain of an IPO stock's closing price on its first trading day relative to the offer price. A pop of 15–20% is considered ideal, balancing investor satisfaction against the issuer leaving money on the table. A 0% pop signals market disagreement with the offer price and is considered a failure. A pop exceeding 30% paradoxically signals failure because the issuer could have priced higher. The banker's goal is to engineer a 'just right' pop.
The final IPO issuance price confirmed on Pricing Night, reflecting book-building results. It is typically set at the mid-to-upper end of the pre-announced price range. The decision incorporates oversubscription multiples, order quality, and market conditions. The opening trade price on the first day of exchange listing is determined by supply and demand around this offer price.
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