A-shares are the most volatile and most rule-laden asset class in the mainland universe. The good news: although the rules are fussy, their total volume is finite — one article can cover everything you need to know. We’ll follow the usual order: threshold → rules → fees → personality → who it suits.
Four boards, four thresholds
The A-share market is not one market — it’s four. Inside the same brokerage account, only one of them is enabled by default:
| Board | Code prefix | Opening threshold | Price limit | Company profile |
|---|---|---|---|---|
| Shanghai Main Board | 600/601/603/605 | None | ±10% (ST ±5%) | Large mature companies |
| Shenzhen Main Board | 000/001/002/003 | None | ±10% (ST ±5%) | Large and mid-sized companies |
| ChiNext | 300/301 | ¥100,000 in assets + 24 months’ trading experience | ±20% | Growth-oriented innovative companies |
| STAR Market | 688 | ¥500,000 in assets + 24 months’ trading experience | ±20% | Hard-tech companies |
| Beijing Stock Exchange | 8xx/920 | ¥500,000 in assets + 24 months’ trading experience | ±30% | Small and mid-sized innovative companies |
A few key points:
- “24 months of trading experience” counts from the first stock trade in any account under your name. It’s tracked nationally, and switching brokers doesn’t reset it. So completing your first trade as early as possible (even just one lot of a cheap stock or one lot of an ETF) is unlocking boards for yourself two years from now.
- The thresholds for ChiNext, the STAR Market, and the Beijing Stock Exchange are all based on average daily assets over the 20 trading days before you apply. Temporarily transferring in a large sum works, but assets borrowed through margin financing don’t count.
- New stocks have no price limit during their first 5 trading days (the rule after the full registration-based IPO system); from day 6 onward the table above applies. Movement in those first 5 days can be any number at all — the era of “mindlessly holding” an IPO allotment after winning the lottery is over.
T+1: what you buy today can only be sold tomorrow
A-shares follow T+1: stocks bought today can only be sold on the next trading day; cash from stocks sold today can buy other stocks the same day, but can only be transferred out to your bank card on the next trading day.
The direct consequence of this rule is: you cannot correct a mistake on the same day. Chase a rally in the morning, watch it dive in the afternoon, and all you can do is watch — there is no action available to you. This stands in sharp contrast to convertible bonds (T+0) and gold ETFs (T+0), and it’s the fundamental reason many strategies that don’t work on individual A-shares do work on convertible bonds.
Paired with T+1 is the price limit: except on a stock’s listing day, once the price hits the daily limit up or down, orders can only queue for execution. At limit-down, your sell order may wait in line all day without ever getting filled — in extreme markets, “being able to sell” is itself a scarce resource. If a quantitative strategy’s backtest ignores price limits, the results will look implausibly beautiful; live trading will teach you humility.
Round lots and odd lots
- Main Board and ChiNext: 100 shares = one lot, and buys must be in multiples of 100 shares. One lot of Kweichow Moutai costs about ¥150,000; one lot of a cheap stock costs only two or three hundred yuan — “you can trade stocks with a few hundred yuan” and “I can’t afford it” are both true, depending on which stock you buy.
- STAR Market: 200 shares minimum, and beyond 200 shares you can increase in single-share increments (e.g., 201 shares).
- When selling, odd lots under 100 shares (created by dividends and bonus share issues) can be sold all at once.
IPO subscription: a lottery that requires a ticket
A-share IPO subscription uses a market-cap allotment system. The rules are simple once unpacked:
- The ticket: over the 20 trading days counting back from two trading days before the subscription date (T-2), your average daily holdings of unrestricted shares in the corresponding market must reach ¥10,000 to qualify. Shanghai and Shenzhen market caps are counted separately — each plays its own game.
- The quota: the higher your market cap, the more shares you can subscribe for, but there’s a cap (maxing out the subscription usually requires market cap in the hundreds of thousands of yuan).
- The allotment: a lottery, with winning rates typically in the range of a few ten-thousandths. If you win, just pay on time; failing to pay after winning three times within a year gets your IPO subscription rights suspended for six months.
- The cost: no funds are frozen at subscription time (credit-based subscription) — it’s effectively a zero-cost lottery ticket.
Two things to note: the market-cap ticket requires stocks — ETFs and convertible bonds don’t count; and the myth that new listings never lose money died with the registration-based system. Breaking issue price (falling below the offering price on debut) is now normal, and IPO subscription has gone from “free money” to a small decision that requires a glance at the company’s quality.
As for fees, the full cost of stock trading (commission, stamp duty, transfer fee) gets a unified breakdown in Part 6, the account article. Here, just one order of magnitude: the total friction cost of one buy plus one sell is roughly between 0.1% and 0.01%, depending on your commission rate. Irrelevant for low-frequency traders; a matter of life and death for anyone who wants to trade small swings at high frequency.
The personality of A-shares
- High retail participation — sentiment-driven volatility is larger than in mature markets, and sector themes rotate fast.
- Short bulls, long bears is the statistical signature of the past thirty years: most of the time the market grinds down or sideways, with occasional explosive rallies. This means the experience of going all-in at once is usually terrible; regular fixed-amount investing or phased entries are postures better suited to this market.
- High policy sensitivity: an industry policy can directly destroy an entire sector’s valuation logic (think of the tutoring industry). The more concentrated your holdings, the more lethal this risk becomes.
Who it suits
Suitable for: people who can watch a floating loss of over 30% without losing sleep, who are willing to spend time doing homework on individual companies, or who simply use a small position to experience the market. Not suitable for: people who put money they’ll need within six months into stocks, or people who feel physically unwell when their account turns green (in China, green means down).
For most beginners, the more sensible path is to first earn the market’s average return through the index funds/ETFs of Part 3, and treat individual stocks as a learning position — one small enough that losses affect your mood but not your life.
Thresholds and rules change with regulatory adjustments. Before acting, check the latest announcements from the Shanghai, Shenzhen, and Beijing exchanges and your broker. This article does not constitute investment advice.