How SGX Trading Works: CDP Accounts, Contra Trading, Odd Lots and Corporate Actions

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Last updated: 16 October 2026 · By Spencer Li, CFTe

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When you buy a share on SGX, 2 things happen on 2 different days. The trade is agreed the moment your order fills. The shares and the cash only change hands 2 business days later, which SGX calls T+2. Almost every confusing word in Singapore stock trading, from CDP to contra to buying-in, lives in the gap between those 2 days.

In short, your shares sit either in your own CDP account at the Central Depository, or in a custody account with your broker. Contra trading is buying and selling the same stock inside that 2-day window, so only the difference is settled. An odd lot is any quantity smaller than a board lot, and it trades on SGX’s separate unit share market. Corporate actions are what the company does to your shares, such as paying a dividend or offering rights, and what you get depends on what sits in your account on the record date.

2 of these changed in 2026, so much of what you will find online is already out of date.

Where do your SGX shares actually sit?

In one of 2 places: a CDP direct account, or a custody account run by your broker.

The CDP Depository Rules say CDP opens a “Direct Securities Account for an individual or corporation which holds the Deposited Securities beneficially for his or its own account.” You get one, because “A person shall not have more than one Direct Securities Account”. CDP sends a statement each month you trade, and a holdings statement at least every 6 months.

The second route is growing fast. In its 1 July 2026 release, SGX said “six such accounts opened for every direct account opened with CDP over the period from October 2024 to April 2026”, meaning broker custody accounts. From 15 July 2026, depository agents may also hold SGX shares for clients “in omnibus broker custody accounts”, the model most overseas markets already use.

Does the choice matter? Mostly when the company does something. In a direct account, the dividend, the rights offer and the meeting notice come to you. In a custody account they come through the broker. SGX said it will bring in “minimum service standards for brokers and depository agents to facilitate the exercise of shareholder rights”, covering “handling of corporate actions and assisting attendance at shareholder meetings”, by the end of 2026. Personally, I would ask any broker how it handles a rights issue before parking a long-term holding there.

What does T+2 mean for your cash?

T+2 means the trade settles 2 business days after the trade date. SGX moved to it on 10 December 2018. Its FAQ gives the example of a Monday trade with no holiday in between: “the settlement date will be Wednesday.”

Buy on Monday and the cash is due on Wednesday. Sell on Monday and the shares are due on Wednesday. Every term below describes what happens when one side of that does not turn up on time, which is why I call this the T+2 clock. Once you can see the clock, contra, buying-in and the ex-date all make sense on their own.

[INFOGRAPHIC: the T+2 clock as a 3-day strip, Monday trade, Tuesday contra window, Wednesday settlement and buying-in, with the record date and ex-date shown below it]

What is contra trading, and how does a contra loss happen?

Contra trading is buying and selling the same stock inside the settlement window, so only the difference is paid. A 2014 MAS and SGX consultation paper listed 3 features. First, “customers do not have to put up any collateral for their trades.” Second, a buy on trade day T “is offset by a sale transaction of the same security within the settlement cycle”. Third, “the offsetting trades are settled on a net basis.” The paper was written when the cycle was T+3. Today it is T+2.

The same paper found that “about 31% of total trading value on SGX is due to contra trading” between October 2012 and October 2013.

Here is a contra loss, with hypothetical numbers. You buy SGD 10,000 of a stock on Monday without that cash in your account. By Tuesday it has fallen 4%, and you sell. You never pay the SGD 10,000. You do pay the difference, which is about 4% of the position plus 2 sets of fees, in cash, by the deadline your broker sets.

Had it risen 4%, you would collect a contra gain. That appeal is also the problem. You controlled SGD 10,000 of stock with nothing down, so a 10% gap on bad news costs you 10% of a sum you never had.

A new investor on r/askSingapore hit this in April 2025, after an order filled with too little cash in the account. “I got no idea what the meaning of sell contra… pls help… afraid will affect my existing shares”. The position must be paid for or sold, and your broker’s terms decide what happens if neither is done. Read them before the first contra trade.

If you want a daily routine that keeps each trade inside a plan, the free 15-Minute Swing Trader’s Checklist is at the end of this post.

What happens if you sell shares you do not have?

CDP buys them for you, at your expense. That process is called buying-in.

MAS’s Guidelines on the Regulation of Short Selling describe it. CDP buys “securities on behalf of sellers who do not possess securities for delivery on settlement day”. Then “the cost of purchase and an additional penalty is charged to the seller who failed to deliver the securities.” Under CDP Clearing Rule 6.7.4, the buying-in bid is set at “2 minimum bids above the highest of” the previous close and the recent traded and bid prices. So you buy back above the market, by design.

Then come the fines. Clearing Rule 6.7A.1 lets CDP fine the clearing member “$1,000 or 5% of the contract value of the undelivered securities (whichever is higher)”, rising to “$5,000 or 10%” if a trade from the buying-in market also fails. SGX’s FAQ adds that “The Clearing Member may pass on the charges and penalties to the customers that fail to deliver.” On a small trade, the minimum fine can dwarf any profit you hoped for.

Selling first and buying back later has its own rules, covered in short selling explained.

What is a board lot, and what changed in October 2026?

A board lot is the standard trading unit on SGX. SGX cut it from 1,000 units to 100 on 19 January 2015, saying a smaller lot would “make it more affordable for retail investors to invest in a wider range of equities, including blue chips”.

It changed again this year. From 5 October 2026, the lot went “From 100 units to 10 units for instruments priced above $10 and up to $100”. Above SGD 100 it went “From 100 units to 1 unit”. The first round covered 11 stocks priced above SGD 10, which SGX said made up 35% of trading activity in the first half of 2026.

A hypothetical stock at SGD 40 used to need 100 shares, so SGD 4,000, for one lot. At 10 shares a lot, the minimum is SGD 400.

A stock only moves to the smaller lot when SGX’s quarterly review adds it, and the next review is in January 2027. And SGX said “Board lot size reductions will remain even if stocks fall below the $10 and $100 thresholds.”

How do you buy or sell an odd lot?

On the unit share market. SGX’s rules define it as “The securities market operated by SGX-ST in which an order may be matched in any quantity of less than one board lot.”

Odd lots usually arrive by accident. A rights issue or a share consolidation can leave you with 37 shares of a stock that trades in lots of 100. The unit share market is thinner, so the spread can be wider, and a minimum fee is a bigger slice of a small trade.

For stocks with a 1-unit lot, the problem disappears, because every quantity is a full lot.

How do dividends, rights and other corporate actions reach you?

Through your account. Whoever holds the shares on the company’s record date gets the entitlement. Because a trade takes 2 business days to settle, the shares start trading “ex” before the record date. Buy on or after the ex-date, and the dividend goes to the seller.

A scrip election, a rights subscription or a takeover acceptance needs your instruction before a deadline. Direct account holders can file some on the SGX Investor Portal, and custody holders go through the broker. How a dividend from a foreign stock is taxed is a separate question, covered in the post on tax and trading profits.

The wider picture of shares, ETFs and CFDs is in the ultimate guide to stocks and CFDs trading.

So which of these should you actually worry about?

The T+2 clock. Everything in this post is a rule about what happens inside those 2 business days, and almost every costly surprise comes from forgetting that the trade and the payment are separate events. A contra loss is a bill that arrives before you have decided anything. A buying-in fine is the price of selling shares that were never in the account. A missed dividend is a purchase made 1 day too late.

So, do you know which kind of account your shares sit in today, and what your broker does when a rights offer lands?

FAQ

What is contra trading in Singapore?

Contra trading is buying and selling the same SGX stock within the T+2 settlement window, so only the price difference is settled. A contra loss must be paid in cash, plus fees.

How long is the SGX contra period?

Trades on SGX settle 2 business days after the trade date (T+2), the cycle SGX has used since 10 December 2018. Your broker’s own terms set the exact deadline for paying a contra loss.

Do I need a CDP account to buy Singapore shares?

No. You can hold SGX shares in a CDP direct account in your own name, or in a custody account with a broker. SGX said in July 2026 that broker custody accounts were being opened at about 6 for every new CDP direct account.

How do I sell odd lot shares in Singapore?

Odd lots trade on SGX’s unit share market, which matches orders of less than one board lot. Spreads there are often wider, so check the bid and ask before you sell.

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About the author. Spencer Li is the founder of Synapse Trading and a Certified Financial Technician (CFTe). His trade log is public: every trade since April 2024, dated, losses left in.

Educational content only, not personalised financial advice. Trading carries risk, including loss of capital. Past performance is not indicative of future results. Synapse Trading is not licensed or regulated by MAS.

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Educational content only, not personalised financial advice. Trading carries risk, including loss of capital. Past performance is not indicative of future results. Synapse Trading is not licensed or regulated by MAS.