The UK is introducing an innovative new form of regulated trading platform for private companies, known as PISCES. With many companies choosing to stay private for longer, the primary objective of the new platform is to increase the liquidity of shares of participating companies, offering new investors easier access to growth companies pre-IPO and allowing early-stage investors and other shareholders, including employees, to realise their investments. For some companies, the platform may also act as a stepping stone, helping in the journey towards a future public listing.

In this briefing, we look at 10 key features of the PISCES regime.

1. Why is this new type of trading platform called a PISCES?

PISCES is an acronym for a "Private Intermittent Securities and Capital Exchange System". This encapsulates the nature of the new platform – a PISCES will allow private companies to trade their securities on an intermittent basis in a controlled environment.

2. Which companies will be eligible to have their securities traded on a PISCES platform?

Any company, whether UK-incorporated or overseas, will be capable of having its shares traded on a PISCES provided it does not have shares admitted to trading on a public market either in the UK or abroad.

In practice, the PISCES regime will probably most likely be of interest to growth companies and those with a large shareholder base, particularly of employee shareholders.

3. Is there a similar trading platform in another jurisdiction?

The PISCES regime is to some extent modelled after the Nasdaq Private Market which provides a secondary market in the US for private company shares and allows for pre-IPO liquidity solutions.

4. How is the PISCES regime being established and operated?

The PISCES regime is being established by HM Treasury under a financial market infrastructure sandbox¹ (the Sandbox) and will be implemented and overseen by the Financial Conduct Authority (FCA) primarily through a new PISCES Sourcebook. 

A firm wishing to be a PISCES platform operator will need to apply to the FCA for permission. Only firms established in the UK, and which are either a recognised investment exchange or have the relevant permission under the Financial Services and Markets Act 2000, will be eligible to apply. 

5. What are the key features of a PISCES platform?

Platform operators will have scope to shape their individual operating models and service features, allowing for an element of competition between operators and giving companies scope to select the PISCES platform most appropriate for their requirements. 

However, all PISCES platforms will have to meet the overarching requirements of the Sandbox, which include the following:

• A PISCES platform can only operate as a secondary market for the trading of existing shares and not as a forum for raising capital through the issue of new shares (though participating companies may be more attractive to primary investors as a result of greater liquidity). Given the additional complexity associated with share buybacks, these will not be permitted at the outset, but this is something that HM Treasury will keep under review.
• A PISCES platform must allow for multilateral trading (i.e. multiple buying and selling interests must be able to interact in the system in a non-discretionary manner). PISCES operators will be required to implement a bespoke trade transparency regime, limited to participating investors, to help ensure fair and orderly markets.
• Trading events on a PISCES platform must be intermittent, meaning "occasional, not frequent and of limited duration". This could include monthly, quarterly, annually or ad hoc trading periods. 
• A PISCES platform must allow participating companies discretion in respect of one or more of the following:
  • when their shares are traded;
  • who is allowed to buy them;
  • any other trading restrictions, including a minimum or maximum price;
  • who may receive information about the company or transactions.

A company with shares admitted to a PISCES platform will therefore have discretion over these matters, subject to the rules of the relevant platform and the overarching requirements of the Sandbox.

6. Who will be eligible to buy and sell a participating company's shares on a PISCES platform?

Institutional and professional investors will be eligible to buy shares on a PISCES platform. In addition, the following limited categories of retail investor will also be eligible:

• certain sophisticated and high-net-worth investors;
• in relation to a particular company, employees, directors and officers of (and certain services providers to) that company, plus their equivalents in the company's immediate corporate group if their work relates to the company (Qualifying Individuals).

However, there will be no obligation on PISCES operators to market their platforms to all types of eligible investor. As mentioned above, PISCES platform rules may also allow participant companies to impose restrictions on who can buy their shares. Broadly, a participating company will be able to impose restrictions on who can buy where this serves to protect the legitimate commercial interests of the company.

On the sell-side, a participating company will not be able to restrict an existing investor from selling at a trading event unless that is consistent with existing contractual obligations applicable to the investor as a Qualifying Individual.

The proposed FCA Sourcebook assumes that buyers and sellers will not interact directly with the operator of the PISCES platform but will do so through a broker, as is the case on public markets.

7. What corporate information will a participating company have to disclose?

In line with the "private-plus" regulatory approach of the Sandbox, the UK Market Abuse Regulation (which applies to companies traded on the UK's public securities markets) will not apply. Instead, there will be a bespoke disclosure-based regime for participating companies.

Central to this will be the requirement for a participating company to disclose certain "core information" in advance of a trading event. The core information will include:

• a business and management overview, financial statements and information about any significant changes since the date of the latest published information;
• details relating to its share capital, including any employee share schemes, major shareholders and beneficial owners;
• information about directors' previous transactions in the shares of the company and their trading intentions for the trading event;
• information about material contracts and material company-specific risks;
• information on whether price parameters are being applied in connection with the trading event together with historic trading data and information regarding commitments on holding future trading events.

Subject to the rules of the relevant PISCES operator, a company may withhold core information in certain circumstances (e.g. if disclosure would be likely to prejudice the legitimate interests of the company or cause it to breach contractual arrangements).

More generally, PISCES operators will be able to require participating companies to disclose additional information where the core disclosure information is not sufficient adequately to inform investors.

In most cases, the regime will apply a negligence standard to disclosures. This means that a participating company will not have liability to compensate investors if its officers reasonably believed the core information to be true and not misleading. However, in some cases, such as forward-looking information, a company will only be liable if its directors were fraudulent or reckless.

8. How will corporate disclosures be made?

Information disclosures will not have to be made public. Instead, a PISCES platform operator will have to ensure they are made available in a secure environment to all investors entitled to participate in a particular trading event and that they remain available until the end of that trading event.

All disclosures will be supplemented by risk warnings from the PISCES platform operator, including a warning that disclosures are not approved by the platform operator or the FCA. (Additional risk warnings and other protections will also apply in the case of eligible retail investors.)

9. Will there be any special tax rules for transactions on a PISCES platform?

The government is introducing exemptions for stamp duty and stamp duty reserve tax for transfers of shares that take place on a PISCES platform.

It has also published a technical note on how PISCES trading events will interact with two tax-advantaged share schemes (Enterprise Management Incentives and Company Share Option Plans) and confirmed that it will introduce legislation to allow employers, with their employees' permission, to amend existing contracts to include a PISCES trading event as an exercisable event, without losing the tax advantages the schemes offer.

10. When will the PISCES regime go live?

As yet, there is no firm date. However, it is likely that the PISCES regime will go live in the second half of 2025.

The principal legislation is now in place² and the FCA is finalising its PISCES Sourcebook. It expects to publish this in June 2025³, after which those wishing to operate a PISCES platform will be able formally to apply to the FCA. Several potential operators are known or have been reported to be interested. 

The Sandbox will run for five years and a decision will be taken during this time on whether to move the PISCES regime to a permanent legal framework.

1. The Financial Services and Markets Act 2023 gave HM Treasury power to introduce financial markets infrastructure sandboxes (with modified or disapplied legislation) to facilitate the testing of new technologies in financial services.↩
2. The Sandbox is being introduced primarily through the Financial Services and Markets Act 2023 (Private Intermittent Securities and Capital Exchange System Sandbox) Regulations 2025 which come into force on 5 June 2025.↩ 
3. Update June 11, 2025: The PISCES Sourcebook was published on June 10, 2025.↩