# Hyperliquid SNDK: Inside Entropy's io:SNDK SanDisk Perp

> io:SNDK is the only ticker Entropy and trade.xyz both list. The spec, the 10x cap, the LULD bands, the funding multipliers and the open interest cap gap.

*Source: https://entropyguides.com/guides/trading/sandisk-sndk-perp*

> **Note:** **io:SNDK in 40 words:** Entropy's own cash-settled perp on SanDisk Corp., 10x max leverage, isolated margin only, 24/7. Priced against SanDisk's public print in the cash session and against Entropy's own book inside a plus or minus 10% band outside it. Data checked 26 August 2026.

Of the 319 markets reachable through [Entropy](https://entropy.io/trade/SNDK?r=concept211)'s frontend, `io:SNDK` is the one that lets you compare Entropy against the HIP-3 incumbent on identical terms. SanDisk is the **only ticker that both Entropy and trade.xyz list**, which makes it the cleanest head-to-head in the entire HIP-3 cohort. Same underlying, same settlement layer, same fee schedule, two different books.

On 26 August 2026, Entropy's `io:SNDK` did **$53.9M of 24-hour notional against trade.xyz's $178.8M on `xyz:SNDK`**, so Entropy held roughly **23.2% of combined SNDK volume**. Castle Labs measured 12% the day before, on 25 August. The share roughly doubled in a day, which means any article still quoting 12% is already stale, and it also means this figure has a short shelf life. Re-pull it before you rely on it. Ours is stamped 26 August 2026 and pulled from the Hyperliquid `info` API.

![The io:SNDK terminal on Entropy showing the SanDisk perp order book, chart and the 10x leverage badge.](/images/shared/entropy-sndk-terminal.webp)

## Contract specification

| Parameter | Value |
|---|---|
| Symbol | `io:SNDK` |
| Reference issuer | SanDisk Corp. |
| Deployer | Entropy, HIP-3 ticker `io` |
| Quote and collateral | USDC |
| Maximum leverage | **10x** |
| Margin mode | **`strictIsolated`** |
| Depth constant *a* | 1,000 |
| Growth mode | enabled, since 19 Aug 2026 14:12 UTC |
| Market type | US Equity |
| Trading hours | 24/7 |
| Scheduled terminal date | none |
| First trade | 19 Aug 2026, 14:00 UTC |

Two entries there deserve their own sections, because both of them are places where the published spec and the live system do not line up.

### The margin mode contradiction

Entropy's risk and margining documentation says *"Strict Isolated: Not enabled."* The Hyperliquid API disagrees. Query `{"type":"meta","dex":"io"}` and `io:SNDK` comes back with `"marginMode":"strictIsolated"` and `"onlyIsolated":true`. So does `io:ANTH`.

Trust the API. It is the enforcement path, and the practical effect is that you cannot put an `io:SNDK` position into cross margin. Every position is collateralized by the margin you assign to it and nothing else, which caps your downside at that position's margin and also means a well-funded account cannot rescue a position that is heading toward liquidation. If you are used to running cross margin on Hyperliquid core perps, this changes how you size.

### The open interest cap discrepancy

This one matters more, because it determines whether you can open a position at all.

| Source | Reported OI cap for `io:SNDK` |
|---|---|
| Entropy's asset directory (docs) | **5M** |
| Hyperliquid API, `perpDexLimits` for dex `io` | **10,000,000** |

We queried both on 26 August 2026 and got that split. **Trust the API.** The cap that rejects your order is the one the chain enforces, not the one on the documentation page. At the time of checking, `io:SNDK` open interest was about $4.73M, which is 47% of the API figure and 95% of the documented figure. If you had been trading against the documented number you would have been expecting the market to stop accepting new positions imminently, and it was not close.

For comparison, `io:ANTH` runs a $5M cap and had been sitting near two thirds of it, which is the market where cap rejections actually bite. If you hit one, [cannot open position](/troubleshooting/cannot-open-position) covers the diagnosis.

## How io:SNDK is priced

An equity perp has a problem a crypto perp does not: the thing it references stops trading every afternoon. Entropy's specification handles this by running two distinct regimes and switching between them at the session boundary.

**During SanDisk's regular cash session**, the oracle is pinned to the public reference price:

> O(t) = P_pub(t), and M(t) = (P_pub(t) + I₃(t)) / 2

The oracle is simply the public print. The mark, which is what drives your unrealized PnL, margin, liquidation triggers and stop and take-profit triggers, is the mean of the public print and a 3-minute EMA of Entropy's own mid. Entropy's stated rationale is that neither leg can move the mark by more than half of its own displacement, so a dislocation on one side is damped by the other.

**Outside the cash session**, there is no live public price, so the oracle becomes a liquidity-weighted blend of Entropy's internal price and an external price, and the mark becomes Entropy's own 5-minute EMA clipped to bounds centered on the last public print:

> L = (1 − 1/ℓmax)·P_last, U = (1 + 1/ℓmax)·P_last, and M(t) = clip(I(t); L, U)

With ℓmax = 10 on `io:SNDK`, those bounds sit 10% either side of the closing print. The slower 5-minute EMA is used overnight because the internal price is carrying the mark on its own without a public anchor.

The blend weight in the overnight oracle is driven by executable depth within 200bps of the mid, with each resting order discounted by an expected fill ratio ρ = 1/(1 + exp(0.15·d_bps)). The internal weight is capped at 0.95, so the external side always keeps at least 5% weight. Entropy describes the depth heuristic as intentionally omitting queue position, volatility and flow variables.

Venue-declared intraday halts and stale-feed conditions during the regular session are treated as outside market hours until trading resumes or the feed recovers. That is worth remembering on a day SanDisk halts for news: the perp does not stop, it switches regime.

## LULD: the plus or minus 10% overnight cage

This is the mechanic that will reject your order, and it is the one most people meet by surprise.

Outside the cash session, trading on `io:SNDK` is confined to a band placed one initial-margin fraction above and below the reference price. Let P_ref be the last published oracle value while the external feed was live, that is, the price at the moment SanDisk's session closed. P_ref is held fixed for the whole non-trading window and does not update from internal flow. With Λ = 10 as the market's maximum leverage, the initial margin fraction is 10%, so:

> P⁺ = P_ref × 1.10, P⁻ = P_ref × 0.90

Entropy's documentation is unambiguous about the consequence: *"Orders that would execute through a band are rejected, and the market rests limit-up at P⁺ or limit-down at P⁻ until flow re-enters the band or the underlying's session reopens."*

So an overnight news event that would move SanDisk 15% cannot move `io:SNDK` more than 10% until the cash session reopens and the bands are released. That protects the mark from being walked arbitrarily far by internal flow with no external price supporting the move. It also means the perp can sit pinned at limit-up while everyone who wants to buy is unable to, and it means a gap on the reopen is a real possibility rather than a theoretical one, because the bands are released and the oracle returns to its standard construction on the next tick.

> **Warning:** **Band width scales inversely with max leverage.** The 10% band on `io:SNDK` comes directly from its 10x leverage cap. A market with 5x max leverage gets a 20% band, and a market with 20x gets 5%. Higher advertised leverage means a tighter overnight cage, which is the opposite of the intuition most traders bring.

## Funding

Funding accrues continuously and pays hourly. The hourly rate comes from the premium of the perpetual mid against the oracle using the standard Hyperliquid funding formula, scaled by a per-market multiplier m:

| Regime | Multiplier m |
|---|---|
| SanDisk market hours | **0.5** |
| Outside market hours | **0.125** |

The payment is Q × O(t) × f(t), where Q is position size and O(t) is the **oracle** price rather than the mark. Funding is peer to peer, and Entropy states plainly that the exchange takes no fee on funding payments.

The practical read: overnight funding on `io:SNDK` is damped to a quarter of its daytime scaling. A basis that opens up while the cash market is closed costs a quarter as much per hour to hold as the same basis during the session. That is a different profile from `io:ANTH`, where the pre-IPO multiplier is 0.00125, roughly one eighth of the Hyperliquid default, and funding is close to negligible. If you carry positions across regimes, model the two multipliers separately.

## Corporate actions, and what happens at the end

`io:SNDK` has no scheduled terminal date. Unlike `io:ANTH`, which carries a no-IPO resolution dated 18 August 2028, an equity perp on Entropy runs until a corporate action ends the public reference feed. Entropy's documentation specifies three cases.

| Event | What happens |
|---|---|
| **Cash dividend** | **No adjustment is applied.** The oracle follows the public reference price through the ex-dividend date and the perpetual reprices with the underlying. |
| **M&A or delisting** | The market settles to the last price one day before SanDisk's final trading day on its primary venue, via `haltTrading`. |
| **Stock split** | Because position sizes cannot be resized on this venue, the market settles to the last price one day before the primary venue's ex-date via `haltTrading`. A successor market on the post-split basis may be listed once post-split public prices are observable. |

The dividend treatment is the one to internalize. A long position in `io:SNDK` does not receive the dividend and does not get compensated for the ex-date drop. You hold the price move without the cash. On a stock with a small yield this is noise. On a stock with a meaningful one it is a scheduled, known, one-directional cost of carrying a long across the ex-date, and it is the sort of thing a synthetic gives you that the underlying does not.

The split treatment is worth reading twice as well, because "settles to the last price one day before the ex-date" means your position closes at that mark whether you wanted it to or not, and a successor market is described as something that *may* be listed rather than something that will be.

## Fees

HIP-3 markets are charged at twice the standard Hyperliquid validator-operated perp rate, with the protocol fee split evenly between Hyperliquid and the deployer. That is the published 0.030% maker and 0.090% taker. But `io:SNDK` has had growth mode enabled since 19 August 2026, which scales all fees, rebates and volume contribution by 0.1.

| | Base perp | HIP-3 (2x) | With growth mode |
|---|---|---|---|
| Maker | 0.015% | 0.030% | **0.0030%** |
| Taker | 0.045% | 0.090% | **0.0090%** |

We cross-checked the effective figure at the dex level rather than trusting the arithmetic alone: $66.19M of 24-hour `io` notional at 0.009% implies $5,958 of fees, and DefiLlama reported $5,982 for the same window, a ratio of 1.00.

The qualification matters, though. Growth mode is a HIP-3 lever available to every deployer, and trade.xyz runs it on its markets too, reaching 0.00288% taker at its top volume tier. So on the SNDK head-to-head specifically, fees are not the differentiator. Liquidity is. Full working in [Entropy fees explained](/guides/fees/entropy-fees-explained).

## Risks specific to this market

![Entropy's auto-deleveraging documentation stating that HIP-3 markets have no liquidator vault backstop and that ADL cannot be opted out of. Note this is a documentation capture, taller than the terminal screenshot above.](/images/shared/entropy-docs-adl.webp)

**No liquidator vault backstop.** Entropy's own ADL page states that because HIP-3 markets do not have a liquidator vault backstop, auto-deleveraging is the immediate fallback after order-book liquidation, and that ADL cannot be opted out of. On a market whose book can be thin overnight while pinned at a band, that fallback is closer than it is on a core Hyperliquid perp.

**Liquidations are mark-driven.** The mark on `io:SNDK` is anchored to SanDisk's public print during the session, which is reassuring, and to Entropy's own clipped internal EMA outside it, which is less so. Maintenance margin is tiered, with r_mm set at half the maximum initial margin rate. Positions above $100K notional receive an initial liquidation order at 20% of the position followed by a 30-second cooldown.

**One key can end the market.** The `registerAsset`, `haltTrading`, `setFeeRecipient`, `setMarginModes` and `setDeployerFees` powers for the `io` dex sit on a single address. Per Hyperliquid's HIP-3 documentation, `haltTrading` cancels all orders and settles positions to the current mark price. That is the same mechanism the corporate-action rules above invoke, which means the operational path for an intentional wind-down and the operational path for an M&A settlement are identical.

**The venue is a week old.** First `io:SNDK` trade was 19 August 2026. There has been no publicly reported security incident, oracle manipulation or bad-liquidation event on Entropy, and with seven days of history that is expected rather than reassuring. Our full read is in [is Entropy safe](/privacy/is-entropy-safe).

## Who deploys what, and why it matters here

`io:SNDK` is **Entropy's own market**, deployed by Bursa Global Inc. under the `io` HIP-3 ticker. So is `io:ANTH`. Those two are the complete list.

The other 317 markets on Entropy's frontend belong to other deployers, and responsibility for their specification, pricing and settlement sits with whoever registered them. `xyz:SNDK`, `xyz:SPCX` and the S&P 500 and gold markets you can reach through the same interface are trade.xyz's markets. The `para:` tickers belong to Paragon, and `mkts:` belongs to Markets by Kinetiq. Entropy distributes trade.xyz's inventory while competing with trade.xyz for deployer fees, and `io:SNDK` against `xyz:SNDK` is where that competition is directly measurable.

That also constrains the referral rebate. Entropy's tiers apply *"only to activity on Entropy deployed markets"*, so trading `io:SNDK` earns the rebate and trading `xyz:SNDK` through the same frontend does not. And the tiers are calculated against Entropy's roughly 50% share of the HIP-3 fee rather than the fee you pay, so the entry tier's 25% works out to about 12.5% of your actual fees. Detail on our [referral page](/referral).

[Get started](https://entropy.io/?r=concept211)

## Where io:SNDK fits

If you want equity exposure with 24/7 hours and USDC collateral, `io:SNDK` gives you a 10x isolated perp with a public-print anchor during the session and a 10% cage outside it. If you want pre-IPO exposure instead, [io:ANTH](/guides/trading/anthropic-pre-ipo-perp) is a different animal with a 3x cap, a mark built entirely from Entropy's own book, and a settlement date in 2028. The category mechanics are in [pre-IPO perps explained](/guides/trading/pre-ipo-perps-explained) and [HIP-3 explained](/ecosystem/hip-3-explained), and the deployer comparison is in [HIP-3 deployers compared](/ecosystem/hip-3-deployers-compared).

To trade it you need USDC on Arbitrum One and a funded Hyperliquid account. Start with [how to trade on Entropy](/guides/getting-started/how-to-trade-on-entropy) and [depositing USDC](/guides/getting-started/deposit-usdc-to-entropy). If you are in the United States, Canada, Panama or the United Kingdom, Entropy's frontend returns a trading restriction, covered in [Entropy restricted countries](/privacy/entropy-restricted-countries).

An equity perpetual is not equity and Entropy says so in its own documentation. Nothing on this page is financial, legal or tax advice, and every figure here is a snapshot from 26 August 2026 on a venue that is one week old. See our [methodology](/methodology) for how these numbers were pulled and our [disclaimer](/disclaimer) for the rest.