A Beginner’s Guide to Investing in U.S. IPOs: The New-Issue Subscription Process and Participation Strategies

TL;DR: U.S. IPOs (Initial Public Offerings) work very differently from Hong Kong IPO subscriptions. Channels for Hong Kong retail investors to subscribe directly are limited, but you can still participate via some brokers’ internal subscription windows. This article explains the U.S. IPO subscription process, eligibility requirements, allocation mechanisms, and risks to help you fully understand how to invest in U.S. new listings.

Every year, many companies list in the U.S. market, including high-profile emerging players in technology, artificial intelligence, and biotechnology. For Hong Kong investors, taking part in U.S. IPOs is one way to access high-growth companies globally. However, because the subscription mechanism differs fundamentally from Hong Kong’s, insufficient understanding can lead to missed opportunities or unnecessary risks.

Starting with what a U.S. IPO is, this article breaks down the entire listing process, retail subscription methods, allocation principles, and the key risk factors you should understand before participating, enabling you to make informed investment decisions.

What is a U.S. IPO?

IPO stands for Initial Public Offering, commonly translated as “首次公開招股” or “首次公開發行” in Chinese. In simple terms, an IPO is when a private company sells its shares to the public for the first time and lists them on a stock exchange.

Companies choose to IPO primarily to raise capital via the public markets for business expansion, R&D, or debt repayment. At the same time, an IPO gives early investors, founders, and employees an opportunity to realize gains by selling shares in the market.

The United States is one of the world’s largest IPO markets. Companies may list on the New York Stock Exchange (NYSE) or Nasdaq. Under U.S. Securities and Exchange Commission (SEC) rules, a company must file a Form S-1 prospectus before its IPO, disclosing its financials, business model, and related risks.

Overview of the U.S. IPO Listing Process

Understanding the overall U.S. IPO process helps you grasp when you can subscribe and what each key timeline means.

Phase 1: Preparing to list

After deciding to go public, the company engages an investment bank (the underwriter) to assist with preparations and submits Form S-1 to the SEC, formally initiating the listing procedure. The underwriter evaluates the company’s valuation, sets the price range, and coordinates the subsequent subscription process.

Phase 2: Roadshow and pricing

Company management and the underwriter conduct a “roadshow,” introducing the business to institutional investors and gathering feedback on pricing, ultimately determining the IPO offer price.

Phase 3: Listing

After pricing, the shares are officially listed and begin trading on the exchange. For most retail investors, this is typically the point at which they can buy the stock directly.

Important note: A key difference between U.S. IPOs and Hong Kong IPO subscriptions is that the U.S. does not have a public subscription mechanism like Hong Kong’s. According to Fidelity, typical U.S. IPO share allocation follows roughly a 90/10 split—about 90% prioritized for institutional investors (e.g., mutual funds, hedge funds), leaving relatively limited allotment for retail investors (Source: Fidelity, IPO Share Allocation).

How can Hong Kong retail investors participate in U.S. IPO subscriptions?

Although direct subscription channels are limited, Hong Kong investors can still participate through the following main avenues.

Approach 1: Subscribe via a brokerage’s internal new-issue window

Some online brokerages act as joint bookrunners or selling group members for U.S. IPOs, obtaining a certain number of new shares and then opening subscription access to their clients.

These brokerages typically provide a “New Issues” or “US IPO” section in their apps. The interface is similar to Hong Kong IPO subscriptions and the process is relatively straightforward. However, note:

• The broker’s new-issue allotment is limited, so the number of shares available is far fewer than for Hong Kong IPOs
• Some platforms impose eligibility requirements, such as account type or asset level
• Submitting a subscription does not guarantee an allocation; popular deals are often heavily oversubscribed

For more on U.S. new-issue subscriptions, see related tutorials at Longbridge Academy.

Approach 2: Buy in the secondary market after listing

For many Hong Kong retail investors, a more direct way to participate is to buy in the secondary market after the stock is officially listed. This allows you to observe first-day performance before deciding whether to enter, rather than subscribing with limited information.

Longbridge Securities offers U.S. stock trading services. Investors can trade newly listed stocks in the secondary market after listing. For related product information, see Longbridge Securities’ investment products.

Approach 3: Grey Market trading

Some brokers offer “Grey Market” trading on the day before the official listing, allowing investors to trade the soon-to-be-listed shares ahead of time. Grey Market trading is over-the-counter (OTC), with buyers and sellers negotiating directly. It can serve as an early pricing signal for the market, but liquidity is limited and price volatility risk is higher.

Step-by-step guide to U.S. IPO subscription

If your broker offers U.S. IPO subscription services, the typical process is as follows:

Step 1: Confirm account eligibility

After opening a U.S. trading account, some platforms require completion of an investor questionnaire or eligibility review before you can apply to participate in IPO subscriptions.

Step 2: Review new-issue information

In the broker’s app under “New Issues,” review U.S. IPOs open for subscription, including the price range, subscription deadline, and minimum subscription size (generally starting from 100 shares, subject to each deal’s terms).

Step 3: Submit an Indication of Interest (IOI)

Enter the number of shares you wish to subscribe for and submit an Indication of Interest (IOI). This is a non-binding application indicating your willingness to purchase shares at the IPO price. Importantly, submitting an IOI does not guarantee an allocation.

Step 4: Funds hold for the subscription

Brokers typically place a hold on funds based on the upper end of the price range as subscription margin. Ensure your account has sufficient balance; otherwise, your application may be invalid.

Step 5: Await allocation results

After pricing, the broker will notify you of your allocation. If allocated, the funds are debited; if not, the held funds are released.

Note: The U.S. IPO subscription window is usually short, typically closing one to two business days before listing. For hot deals, the window may close early. Monitor announcements closely.

U.S. IPO allocation mechanics

Understanding the allocation principles helps you set realistic expectations.

Institutional investors have priority

As noted, the majority of U.S. IPO shares are prioritized for institutional investors. Retail allocations are often small—especially for high-profile IPOs with intense demand—resulting in lower individual allocation ratios.

Brokers’ allocation principles

When allocating new shares to clients, brokers typically follow two principles:

• Broad-based principle: Aim to allocate to as many investors as possible to ensure fairness
• Priority by subscription size: After satisfying broad participation, allocate additional shares to investors who requested larger quantities

Which types of IPOs are easier for retail to get?

Generally, income-oriented IPOs such as Real Estate Investment Trusts (REITs) and Master Limited Partnerships (MLPs) may face different levels of institutional competition compared with highly publicized technology or AI-themed IPOs. Retail allocation ultimately varies with demand for each offering. Allocation is not guaranteed and does not predict post-listing price performance.

To track market developments and upcoming U.S. IPOs, use Longbridge Market Data for real-time information.

Key risks of investing in U.S. IPOs

Investing in U.S. IPOs involves multiple risks that you must fully understand before participating.

Risk of trading below the offer price

If the stock trades below the offer price after listing, it is called a “broken IPO.” This is not uncommon, especially when market sentiment is weak or the IPO is aggressively priced. A break implies an immediate paper loss for IPO subscribers.

Risk of overvaluation

Hot IPOs often attract excessive optimism, which may push the offer price well above intrinsic value. Before subscribing, investors should read the prospectus carefully and assess the company’s financials and business outlook.

Elevated initial volatility

In the early days of trading, because the market is still getting to know the company, order flow may be fragmented and price swings are typically larger than for established listed stocks. Be prepared for higher short-term volatility.

Lock-up period (Lock-up Period) risk

After listing, early investors, management, and employees are usually subject to a lock-up period during which they cannot sell their shares, typically 90–180 days post-IPO. When the lock-up ends, a wave of shares may hit the market, pressuring the stock price. Investors should note these dates.

Information asymmetry

Compared with institutional investors, retail investors have less access to company information and analytical resources, creating potential asymmetry when evaluating an IPO. Thoroughly reading the SEC-filed prospectus (Form S-1/F-1) is an important step to understand the company.

Risk warning: Investing in U.S. IPOs involves higher risks. Past performance does not represent future returns. Investors should make decisions based on their financial situation and risk tolerance, and consider waiting to observe post-listing trading before buying.

FAQs

Can Hong Kong retail investors subscribe directly to U.S. IPOs?

Hong Kong retail investors can participate through brokers that offer U.S. IPO subscription services, but this differs from Hong Kong’s public subscription mechanism. U.S. IPOs have no formal public subscription tranche. Retail investors apply through a broker by submitting an IOI, with no guarantee of allocation. For many Hong Kong retail investors, buying in the secondary market after listing is the more common approach.

How much capital is needed to subscribe to a U.S. IPO?

The minimum subscription size for U.S. IPOs generally starts from 100 shares, with the actual amount depending on the offer price of each deal. Some brokers also require a minimum account asset level to access the IPO function. When you subscribe, brokers typically place a hold based on the upper end of the price range.

Is there a deadline for U.S. IPO subscriptions?

Yes. The U.S. IPO subscription window typically closes one to two business days before pricing, so timelines are tight. If demand is strong, underwriters may close the window early. It’s best to confirm your interest in advance.

What is an IPO lock-up period and how does it affect investors?

The lock-up period restricts company insiders (including management, early investors, and employees) from selling their shares for a period after the IPO, usually 90–180 days post-listing. When the lock-up expires, the market may face selling pressure from newly unlocked shares, potentially weighing on the stock in the short term. Investors should watch these dates.

Do Hong Kong retail investors owe taxes after participating in U.S. IPOs?

Under IRS rules, capital gains from U.S. stocks realized by Nonresident Aliens are generally not subject to withholding tax, while U.S.-source dividends are typically subject to 30% withholding unless a lower treaty rate applies (Source: IRS, NRA Withholding). Hong Kong investors usually complete Form W-8BEN when opening a U.S. account to certify non-U.S. residency. Consult a professional tax advisor for specifics, or see the Beginner’s Guide to U.S. Stock Investing to learn more.

Conclusion

U.S. IPOs offer investors the opportunity to participate in early listings of high-growth companies globally, but their mechanics differ markedly from Hong Kong IPOs. When participating in U.S. IPOs, Hong Kong retail investors should understand the limits of subscription channels, the characteristics of allocation, and the specific risks of IPO investing, including potential breaks below the offer price, elevated volatility, and possible selling pressure after the lock-up.

Before making any investment decision, read the prospectus thoroughly, evaluate company fundamentals, and assess your risk tolerance. If you want to dive deeper into various aspects of U.S. equity investing, including analyzing financial statements, assessing IPO valuations, and formulating trading strategies, visit Longbridge Academy for more investor education resources.

Which tools you choose depends on your investment objectives, risk tolerance, market views, and experience level. Regardless of the instrument, you must fully understand how it works, its risk characteristics, and trading rules, and establish a robust risk management plan. You can download the Longbridge App to learn more about investing.