You are using an outdated browser and your browsing experience will not be optimal. Please update to the latest version of Microsoft Edge, Google Chrome or Mozilla Firefox. Install Microsoft Edge

March 20, 2015

Catch Me If You Can: Cases of Stock Manipulation

Bangkok Post, Corporate Counsellor Column

Last year, 23 people were alleged to have been involved in the manipulation of three separate stocks. The investigations and prosecutions in these cases are ongoing. In light of recent events, this article explains the crime of stock manipulation, discusses the seminal Supreme Court decision on the matter, and identifies a potential new tool of enforcement for private citizens through the recently passed class action legislation. 

The sale and purchase of listed stocks are regulated by the Securities and Exchange Act of 1992. Violations of the Act, including stock price manipulation, subject violators to criminal penalties under Section 296, which include imprisonment for up to two years and fines of at least THB 500,000 or twice the value derived from the violations, whichever is higher.

Section 243 of the Act, in brief, prohibits: (1) misleading the general public into believing a stock’s price or trading volume is “normal” when it is not; and (2) engaging in trading behaviors that affect a stock’s price to lure the general public into buying or selling the stock. It defines stock manipulation in two distinct ways, in the following subsections:

  1. No person, by colluding or agreeing with any other person, shall purchase or sell securities in concealment in order to mislead the general public to believe that such securities are purchased or sold in great volume or the price of such securities has changed or has not changed at any time or during any period of time that is not consistent with the normal market conditions; and
  2. No person, either by himself or jointly with any other person, shall continuously trade securities that result in the purchase or sale of such securities that is not consistent with normal market conditions and such trading is made to lure the general public to purchase or sell such securities unless such trading is made in good faith to protect his or her rightful benefit.

In 1992, the Securities and Exchange Commission (SEC) lodged a criminal complaint under Section 243 against 12 individuals who sold and purchased shares of the Bangkok Bank of Commerce (BBC). The case reached the Supreme Court in 1996, presenting an opportunity to examine the relevant law in detail.

The trial court found that the following facts, presented by the prosecution, were proven:

  • Of the 12 defendants, 6 were blood relatives, 3 had the same address, and all 12 traded BBC shares from the same address.
  • The 12 defendants jointly traded BBC shares through 6 securities companies in great volume with prices that were not consistent with normal market conditions.
  • Prior to the alleged violations, beginning on Oct 2, 1992, the share price peaked at THB 15.75 with an average daily volume of 1.9 million shares. From Oct 2-29, the price reached THB 40.75 with a daily volume of 14.2 million shares.
  • The 12 defendants transferred money among each other from January-October 1992.

Considering the irregularities in trading volumes, sale and purchase prices, and the relationships among the defendants, it appeared clear that the defendants had manipulated the stock in violation of Section 243(1) or (2).

Surprisingly, the court dismissed the allegations and found in favor of the defendants, a decision the Supreme Court ultimately upheld. The court looked to the testimony of a key prosecution witness, an SEC official, who testified that trading “in concealment” in Section 243(1) was intended to mean the seller and purchaser had no real intent to trade the stock but rather issued sale and purchase orders to deceive others.

The court then looked to the defendants’ testimony, in which they admitted to purchasing BBC stock. It ruled this was not trading in concealment regardless of whether they disclosed to the public they were engaged in jointly selling and purchasing the stock, and hence it was not a violation of Section 243(1).

Regarding the allegations under Section 243(2), many investors testified they had purchased BBC stock on their own initiative, hoping for a profit, and not due to the “lure” of any person. The court found this testimony convincing and concluded there was also no violation of Section 243(2). Rather than looking at the intent of the defendants to lure the victims, the court appears to have looked at whether the victims were actually lured by the defendants’ trading behavior.

It would therefore appear that the sale and purchase of securities in the manner conducted by the defendants in this case would not amount to manipulation. We take the view that criminal stock manipulation can, and in most cases does, occur using real or apparently bona fide transactions. For instance, a group of manipulators can sell and/or purchase a stock with actual payments to manipulate the market and then later distribute the proceeds among themselves.

While groups of stock manipulators may now be held criminally liable and subject to imprisonment and fines, investors will soon be able to group together to privately protect their rights through a civil class action lawsuit. Violators will be faced with huge claims, as class action legislation has passed the third reading of the National Legislative Assembly and will soon take effect.

RELATED INSIGHTS​ 

August 11, 2026
On July 27, 2026, the State Bank of Vietnam (SBV) released a draft decree proposing amendments to Decree No. 52/2024/ND-CP dated May 15, 2024, on non-cash payments (Decree 52). The draft decree would amend 17 of Decree 52’s 38 articles, with several key changes directly affecting providers of intermediary payment service (IPS). The key proposed changes affecting IPS providers are outlined below. Streamlining IPS Licensing Procedures A central objective of the draft decree is to simplify regulatory procedures for IPS providers. Notably, it would significantly reduce IPS licensing documentation requirements by removing the need to submit enterprise registration certificates, investment registration certificates, and documents evidencing the qualifications of the legal representative and general director. Instead, the SBV would retrieve this information directly from national business registration and other specialized databases, requesting additional documents only where the relevant information cannot be verified electronically or is incomplete. The draft decree also removes the current limit of two rounds for dossier supplementation and shortens processing timelines for several IPS licensing procedures such as issuance, amendment, and reissuance of IPS licenses. The processing time for new IPS license applications would be thereby reduced from 90 to 60 working days. In addition, several continuing IPS business conditions would be removed. For example, IPS providers would no longer be required to maintain certain representations relating to corporate restructuring or the legality of contributed capital. Likewise, the IPS project plan (đề án) would become a one-time application document rather than an ongoing licensing condition. If retained in the final decree, this change could provide IPS providers with significantly greater flexibility to implement post-licensing technology upgrades, system integrations, and corporate restructuring transactions without needing to revisit the originally approved project plan. The draft decree also removes the requirement for the SBV to consult the Ministry of Public
August 11, 2026
Cambodia’s Ministry of Justice has launched a new platform on its official website to publish notices of forced sales issued by each municipal and provincial court of first instance. The platform’s stated purpose is to inform the public and facilitate greater participation in forced-sale auctions conducted in connection with court-ordered enforcement proceedings. How the Platform Works The platform publishes forced-sale notices from courts of first instance across Cambodia’s municipalities and provinces and includes a link where the public can view properties currently subject to forced sale. To participate in a forced-sale auction, individuals can download Khmer-language bidding application forms through links provided on the platform. The form typically requires the applicant’s name, sex, year of birth, identity card number and issue date, and address, together with details identifying the immovable property (including its ownership certificate number), the relevant enforcement case number and date, and the reference to the public auction or tender announcement issued by the court. Completed application forms must be submitted directly to the specific municipal or provincial court that issued the forced sale. For further inquiries about a particular forced sale, interested parties should likewise contact the relevant municipal or provincial court. Forced Sale of Immovable Property in Cambodia The publication of these notices relates to the forced sale procedure for immovable property under Cambodia’s Code of Civil Procedure (CPC). Unlike property seizure by a court, a forced sale is a compulsory execution proceeding—a subsequent enforcement step that arises only after an underlying dispute has been adjudicated and a debtor fails to pay the debt or outstanding amount due under a final and binding judgment or other enforceable title of execution. For the purposes of this procedure, the term “immovable property” under the CPC refers to land, registered buildings, jointly held shares of such property, registered
August 6, 2026
Every month, VAT-registered businesses in Thailand calculate their output and input VAT and file a return to pay the net amount due or claim a refund. Yet a common and costly dispute arises when a business that has paid input VAT to its supplier—and done everything asked of it—later finds that input VAT rejected on the grounds that the tax invoice was issued by “a person not entitled to issue tax invoices.” In these cases, a buyer may have confirmed the supplier’s VAT registration on the Revenue Department’s website, paid through the banking system, received a complete tax invoice, and kept full payment and inventory records. Even so, if the Revenue Department later determines that the supplier did not genuinely make the sale or collected the VAT without remitting it, the department can disallow the input VAT and assess additional tax, surcharge, and penalty—often more than a year after the transaction. A new article from tax and dispute resolution specialists at Tilleke & Gibbins in Bangkok examines how the Revenue Department and the courts approach these disputes, including two recent Supreme Court (Tax Division) decisions confirming that the taxpayer bears the burden of proving a supplier genuinely sold and delivered the goods and received payment. It considers why the VAT registration system offers no legal safe harbor, why the evidentiary burden falls hardest on online and cross-border transactions where buyers and sellers never meet, and how the Revenue Department’s own digital infrastructure could detect non-remitting suppliers at the source rather than shifting the loss to good-faith buyers. The article also sets out practical guidance: how to build a comprehensive “know-your-supplier” file at the time of a transaction, the procedural steps and strict deadlines for challenging a VAT assessment, and why dispute readiness belongs alongside tax planning at the center
August 3, 2026
On July 23, 2026, the Bank of Thailand (BOT) released for public comment its draft Notification on Digital Channel Security, which would significantly expand the scope and stringency of Thailand’s existing mobile banking security framework. If finalized in its current form, the draft notification would extend mandatory security requirements to credit card providers and credit providers, cover internet banking in addition to mobile applications, phase out SMS one-time passwords (OTPs) for transaction authentication, and introduce biometric verification requirements for high-value transactions. The public comment period is open through August 24, 2026. Background The BOT’s existing Mobile Banking Security Notification, issued in 2024, sets minimum security standards for financial institutions, specialized financial institutions (SFIs), and e-money providers, significantly reducing “money-draining app” fraud. However, fraudsters have since shifted to nonbank providers and internet banking channels, prompting the BOT to propose broader security requirements. Expanded Scope of Regulated Entities and Channels The existing Mobile Banking Security Notification covers only financial institutions, SFIs, and e-money providers offering mobile banking services. The draft expands coverage in two key areas: entities and channels. On the entity side, it adds credit card providers and credit providers that offer fund transfers to third parties at other financial service providers or that provide cash withdrawal services to individual retail customers. On the channel side, it broadens coverage to include internet banking in addition to mobile banking. Strengthened Customer Authentication The draft introduces enhanced authentication requirements in three areas: Service enrollment and device changes. Providers must implement rigorous identity verification, notify customers of enrollment results through out-of-band communication channels, and adopt risk-mitigation measures such as cooling-off periods and temporary transaction limits. Transaction-level authentication. Providers must use two-factor authentication for fund transfers, cardless ATM withdrawals, and transaction limit increases. Secure authentication factors. Key requirements include the following: “What-you-know” factors must