Ethena began the new allocations on September 25. It is not making a directional bet that Nvidia, Apple or Tesla will rise. It is extending the same broad piece of financial engineering that has long sat inside USDe's crypto basis book.

A tokenized stock provides the long spot exposure. A roughly equal short perpetual is opened against it. An upward move should benefit the spot leg and hurt the short; a downward move should do the reverse. If that hedge behaves as intended, the more interesting number becomes the funding paid through the perpetual market.

That does not make the return fixed. Perpetual funding changes continuously. It can compress to the point where the trade is not worth running, and it can become negative so that shorts pay longs instead. The spot token and derivative can also stop tracking each other cleanly.

This does not turn USDe into an equity index

USDe remains a synthetic dollar. The equity position is part of a backing and hedging strategy rather than an attempt to pass stock-market performance through to USDe holders.

The distinction extends to the spot instrument itself. Binance describes bStocks as tokenized securities that provide exposure to listed equities. They are not direct shares in the underlying company and do not automatically give holders normal shareholder ownership or voting rights.

The products are issued by BTech Holdings Limited. That inserts an issuer structure between the actual security and the token Ethena holds. For a small retail position that can look like legal plumbing. For a protocol using the instrument as part of the backing architecture of a multi-billion-dollar synthetic dollar, it becomes a material risk layer.

Ethena built an eligibility test before starting the trade

Kairos Research published the framework used to assess the strategy for Ethena's Risk Committee in late August.

A perpetual qualifies only after averaging at least $25 million of one-sided open interest over fourteen days and accumulating at least thirty days of funding history. The underlying must be a listed public security, leveraged and inverse products are excluded, and a matching tokenized spot instrument has to trade on the same venue.

Using market data through August 26, that screen admitted 17 of Binance's matched markets, representing about $2.14 billion of one-sided open interest. Three names qualified on OKX. None did on Bybit or Kraken at that point.

The list is designed to move with the market rather than become a permanent catalogue. The framework uses repeated observations so that a brief burst of open interest cannot automatically promote a young contract into the strategy.

The $150 trillion equity story is not the usable market

Ethena has emphasized the enormous size of global equities when describing the long-term opportunity. That is useful for understanding the ambition, but the relevant constraint today is much smaller: how much bStock and perpetual liquidity can be entered and exited without moving either market.

The risk framework consequently recommends several overlapping position limits. A position should remain below 10% of the perpetual's open interest, below 20% of the token's circulating supply, below half of the visible order-book depth within 1% of mid and below 10% of daily volume on either leg.

The weakest market effectively dictates capacity. A large perpetual does not help much if the matching token can only absorb a fraction of the spot order without substantial slippage.

Carry was already demonstrating why those rules matter. The approved Binance names averaged roughly 18% annualized in late July, according to the Kairos work, but only about 7% by August 26. Two names were negative by then.

That is a useful antidote to reading historical funding figures as a new USDe rate. Ethena has to evaluate funding against trading fees, financing, slippage, dividend treatment and the amount of capital required to keep the position safely margined.

Stocks close; perpetuals do not

Equity basis trading also introduces a clock that does not exist in a Bitcoin hedge.

U.S. stock exchanges close overnight, on weekends and on holidays while crypto-native derivative markets can keep trading. During those hours, the perpetual's liquidation and index machinery has less direct price discovery from the underlying stock market.

Kairos called that closed-market pricing issue the deepest structural risk in the strategy. A hard move in a thinner perpetual market can threaten the short while the matching token may not offer enough independent liquidity to monetize the offsetting gain cleanly.

The tests in the August report were encouraging but young. Across 37 matched earnings events, the underlying stocks moved 9.9% on average while the hedged positions diverged by an average of 20.3 basis points. Across 400 weekend and holiday windows, average divergence was 14.9 basis points.

That is evidence, not a decades-long track record. The same report recommends additional weekend margin, smaller exposure through earnings or simply closing positions before the underlying market shuts when conditions justify it.

The bStock issuer risk cannot be shorted away

Price delta is only one category of risk. Kairos' review highlighted a more basic structural issue: bStock holders do not have a proprietary interest in the shares backing the certificates.

The report therefore recommended that bStock approval be conditional on a side letter covering the custodian and lending restrictions, independent inventory reconciliation, access to audit material, management of the shared contract upgrade key, committed creation and redemption capacity, definitive dividend treatment and a binding process for corporate actions.

Without those protections, the report described the spot leg as unsecured credit exposure to a Binance affiliate rather than a direct claim on the underlying shares.

Ethena says allocations started on September 25. Public information around the launch does not make it possible to determine precisely which provisions of the side letter proposed in August have since been completed. That is an important unresolved detail in assessing the new backing allocation.

There is concentration elsewhere too. On Binance, the token issuer ecosystem, spot venue, perpetual venue and margin infrastructure are closely related rather than independent layers. Ethena says Binance is giving eligible delta-neutral accounts, including Ethena's, lower priority in its auto-deleveraging mechanism. That is intended to lower the chance that an emergency exchange process breaks one side of the hedge, but it does not remove venue risk.

The real diversification is in funding, not stock exposure

The strategic logic is easier to see from the derivatives side. Crypto funding can become unattractive when demand for leveraged longs falls. A USDe basis book concentrated entirely in crypto therefore depends heavily on one family of trading conditions.

Equity perpetuals create another funding pool whose cycles need not align with bitcoin and ether. Ethena is trying to diversify where the carry comes from while continuing to hedge the price of the underlying asset.

Binance is the first venue, not necessarily the last. Ethena's August work contemplated expanding to additional markets as matching spot instruments, liquidity and operational controls meet its requirements.

So the September 25 change is more precise than saying USDe is now backed by stocks. Ethena has taken its long-spot, short-perpetual machinery and attached it to a new asset class. The hedge can neutralize much of the stock-price direction. It cannot neutralize market closures, thin books, corporate actions, token upgrade keys or the legal structure of the instrument sitting on the spot side.