Two of Wall Street's most powerful institutions, Goldman Sachs and Morgan Stanley, have moved to restrict their employees from trading on prediction markets, marking a significant escalation in how the financial industry is grappling with a fast-growing corner of speculative finance. The restrictions, which apply to platforms including Polymarket and Kalshi, reflect deepening anxiety across Wall Street that staff with privileged access to non-public information could exploit these markets in ways that mirror — or legally constitute — insider trading.
The move is emblematic of a broader compliance reckoning that the prediction market sector has largely managed to sidestep until now. Unlike traditional equity or derivatives markets, prediction markets have historically occupied a regulatory grey zone, attracting retail participants and sophisticated traders alike with their real-money wagers on political, economic, and financial outcomes. That relative freedom is now colliding headlong with the structural realities of employing tens of thousands of people who routinely handle material non-public information.
The Insider Trading Problem Is Not Hypothetical
The concern animating bank compliance departments is straightforward, if legally complex: a Goldman Sachs analyst who learns — through internal channels — that a major merger is about to be announced could theoretically place a bet on a related prediction market outcome before any public disclosure. The pay-off mechanics of platforms like Kalshi and Polymarket make such a trade potentially lucrative in ways that existing surveillance systems, built around stock and bond trading, are simply not designed to detect. The opacity of some prediction market structures compounds the challenge for compliance officers who must now map an entirely new category of financial instrument onto existing personal account dealing policies.
What makes this moment particularly consequential is that the restrictions are spreading. Goldman Sachs and Morgan Stanley are not acting in isolation; the language used in reports suggests a systemic tightening across Wall Street more broadly, with multiple institutions revisiting their acceptable use policies for prediction market platforms. This pattern — individual firms independently arriving at similar restrictions — is often a precursor to formal regulatory guidance, and it signals that the industry is not waiting for regulators to act before attempting to manage the risk in-house.
Prediction Markets at a Crossroads
For Polymarket and Kalshi, the implications cut in two directions. On one hand, the reputational association with insider trading concerns — even as a potential risk rather than a documented scandal — poses a meaningful challenge to their ambitions of mainstream legitimacy. Both platforms have invested considerable effort in positioning themselves as serious financial infrastructure, with Kalshi in particular having fought and won regulatory battles with the Commodity Futures Trading Commission (CFTC) to operate legally in the United States. Having Wall Street banks classify their platforms as compliance risks is an uncomfortable narrative to manage.
On the other hand, the attention itself validates the financial gravity these markets have achieved. Prediction markets were, not long ago, dismissed as novelties — academic curiosities useful for aggregating crowd wisdom but hardly relevant to serious finance. The fact that Goldman Sachs and Morgan Stanley feel compelled to issue formal restrictions signals that these platforms have grown into something the establishment can no longer ignore. The risk of insider exploitation only exists if the markets are liquid and material enough to be worth exploiting.
A Compliance Architecture Built for Another Era
The deeper structural problem Wall Street now confronts is that its compliance infrastructure was architected for a world of registered securities, exchange-traded instruments, and identifiable counterparties. Prediction markets, particularly those with blockchain-based settlement like Polymarket — which operates on the Polygon network — introduce pseudonymous participation, cross-border liquidity, and settlement mechanisms that sit outside traditional broker-dealer oversight. Banks can restrict their employees from using these platforms, but enforcing such restrictions across personal devices and international accounts is a materially different proposition from monitoring trades in brokerage accounts that staff are required to pre-clear.
This enforcement gap may ultimately force the hand of regulators. The CFTC, which has jurisdiction over event contracts in the United States, will face growing pressure to develop specific guidance around the employment of regulated entities' staff on prediction platforms. The Securities and Exchange Commission (SEC) may also find grounds for involvement where prediction market outcomes are sufficiently correlated with securities prices to constitute a proxy instrument. Neither agency has yet issued specific rules targeting the employee trading question, leaving banks to construct ad hoc policies in a regulatory vacuum.
What This Means for the Industry
The tightening of prediction market rules by Goldman Sachs, Morgan Stanley, and their peers represents an inflection point for an industry that has thrived in part because serious institutions paid it relatively little attention. That period appears to be ending. As prediction markets grow in liquidity, political salience, and financial materiality, they will increasingly attract the same scrutiny applied to any instrument capable of being traded on inside information. The question is no longer whether formal regulatory frameworks will emerge, but how quickly — and how disruptively — they will arrive. For now, Wall Street's compliance officers are writing the first draft of those rules themselves, one internal policy memo at a time.
Written by the editorial team — independent journalism powered by Codego Press.