Castle Labs said in a report on the evolution of on-chain RWA trading that real-world-asset perpetuals have moved from a fringe category to a structurally meaningful part of crypto derivatives in less than a year. As the market expands into equities, commodities, indices, foreign exchange, pre-IPO names and other assets that do not naturally fit crypto-native exchange design, the usual perpetual model is running into limits around funding-rate uncertainty and liquidity bootstrapping.
The report centers on Variational’s newly launched swap product and presents it as a different way to trade RWAs on-chain. This is not an AMM-style swap. In the report’s framing, it is closer to a traditional finance swap: traders get price exposure to an underlying asset, while the cost of carrying the position is linked to real financing terms rather than to a funding rate that shifts with on-chain long-short demand.
RWA perpetuals grew 120-fold within a few quarters
According to the report, monthly RWA perpetual volume was below $1 billion in October 2025. By August 2026, it had climbed above $120 billion. In the October 2025 to September 2026 data window, monthly volume peaked at $147 billion in July 2026. Castle Labs cited DefiLlama data dated Sept. 8, 2026.
The report identifies October 2025 as the first inflection point, when TradeXYZ launched on Hyperliquid as a HIP-3 deployer. Growth continued from there. By July 2026, RWA perpetuals reached a peak 20% share of all on-chain perpetual trading. In most months, the category represented roughly 12% to 13% of total on-chain perpetual volume, which the report translates into nearly $1 of RWA-related trades for every $8 traded in on-chain perpetuals overall.
Castle Labs added that the segment has also established a $100 billion base volume level since June 2026.
Even with that expansion, open interest remains concentrated. Total open interest in RWA perpetuals stood at $4.9 billion at the time of the report, with the top two protocols, TradeXYZ and Variational, accounting for nearly 90% of the category. The report breaks that out as about 75% for Trade.xyz and about 14.2% for Variational, followed by GMTrade, Lighter, Ondo and others. That set of figures also came from DefiLlama, dated Sept. 8, 2026.
Why standard perpetuals are a poor fit for part of the RWA market
The report notes that perpetuals became one of the most powerful trading tools in digital assets because they are capital efficient and let users take price exposure without holding the underlying asset. In their earlier phase, perpetuals competed largely within crypto-native markets where liquidity and execution depth were the main battleground.
That changes once the same structure is applied to RWAs. Equities, commodities, indices, foreign exchange and pre-IPO assets do not naturally match the listing and market-making patterns common in crypto venues. Under a standard order-book setup, each new market has to bootstrap its own liquidity, usually through incentives, subsidies and outside market makers. On top of that, platforms need a way to support trading outside traditional market hours if they want a 24/7 product.
Castle Labs points to funding-rate uncertainty as another key issue. Perpetuals are built to track an underlying index closely, and they use funding payments to push prices back toward that index. That mechanism is familiar in crypto. In RWA markets, though, variable funding can materially change the profit and loss of a trade, which in the report’s view makes perpetuals less than ideal for this segment.
Swap versus perp: tracking total return instead of only the index price
The report defines swaps as a new primitive in on-chain trading. Like perpetuals, they are linear derivatives, meaning price moves in the underlying flow linearly into contract P&L. The difference is what each product is designed to track.
Perpetuals were built to follow the index price of an asset as closely as possible, which is why they rely on funding rates to encourage rebalancing. Swaps, by contrast, are described in the report as instruments that track the total return of an asset over time.
That distinction shows up directly in carry costs. Instead of a funding rate driven by exchange-level supply and demand, swaps charge position holders once per day, at the close, 5 p.m. Eastern Time. Castle Labs says that fee is better understood as a holding cost based on the real cost of financing the underlying asset in traditional markets.
The report gives separate examples by asset class:
- For equities, the reference is the overnight rate of the index currency, such as SOFR for the U.S. dollar.
- For foreign exchange, it is the overnight rate differential between the two currencies, adjusted for spread.
- For metals, it is the implied overnight cost of borrowing or lending in U.S. dollars.
Castle Labs says those rates are tightly tied to traditional finance because Variational sources them from market-based financing terms provided by its TradFi liquidity partners.
The product also includes dividend treatment. Long positions receive dividend amounts, while shorts pay them.
At launch, swap markets use isolated margin and have set opening and closing times. Variational expects those markets to move toward 24/7 operation over time and to add cross margin within the platform.
The first listed swap markets are US100, US500, XAU, XAG and USOIL. Since launching earlier this month, those markets have generated $3.8 billion in trading volume and reached a peak open interest of $245 million.
Castle Labs argues that the shift from perpetuals to swaps was a necessary step for Variational. Just two months after launch, traditional-finance perpetual products already represented more than 50% of the platform’s trading volume and open interest. Rather than rely on demand-driven funding and frequent fee transfers, the platform is trying to plug directly into traditional liquidity and turn unstable funding into an annualizable, easier-to-model holding cost.
In the swap markets already live, the report says longs generally pay about 4% to 6% annualized, while shorts receive roughly 2% to 3% annualized.
Omni and OLP: how Variational brings external liquidity on-chain
Most perpetual exchanges have to build liquidity inside their own venue. That works for major assets, but the model becomes harder to scale once a platform wants to list a broader range of markets. Every new product needs market makers, inventory, incentives, risk limits and enough two-way interest to support a deep book.
Castle Labs says one of the key differences in Variational’s swap design is how it sources liquidity. The platform executes through request-for-quote, or RFQ, and uses a vertically integrated liquidity provider called Omni. The report describes OLP, short for Omni Liquidity Provider, as Variational’s in-house integrated market maker.
OLP faces liquidity providers in Variational’s RFQ system directly and brings that liquidity on-chain. Because OLP is the counterparty to all trades on Omni, the initial open-interest cap for swap markets was set at $10 million, with increases planned after the team has time to test OLP’s hedging strategy. OLP manages and hedges risk using external liquidity from centralized exchanges, decentralized exchanges and traditional finance sources.
In practical terms, Castle Labs says the setup lets Variational launch new markets without building an order book from scratch. The platform instead needs a price source, reliable RFQ counterparties and OLP hedging. The trade-off, in the report’s words, is not that liquidity risk disappears, but that the design leans more heavily on pricing transparency and risk management.
Because Variational aggregates swap liquidity from traditional finance venues, the products initially follow traditional market hours. The report says 24/7 trading is expected as more venues are aggregated and traditional markets continue to move toward round-the-clock trading.
Execution-cost study: Variational led in most markets and larger sizes
Castle Labs treats execution quality as the central test for whether the swap model works in practice. To measure that, the report compares Variational Swap with major on-chain venues that list TradFi perpetuals, including TradeXYZ, Lighter and Ostium.
The study covers US100, US500, XAU and XAG. Methodology differs by venue type. For order-book venues such as TradeXYZ and Lighter, the researchers pulled live books, sorted them and walked through each level to simulate market-order taker costs. For quote-based venues such as Variational and Ostium, they analyzed published quotes at multiple size points. Execution cost was measured as the average of long and short position costs, which the report says gives a fuller picture of the quoted market.
The report also notes that Lighter and Variational charge no trading fees, so their execution cost comes entirely from spread. Other venues add fees on top of spread, which raises total cost.
US100: 0.47 basis points for a $1 million trade
In US100, Lighter was the cheapest venue for small sizes such as $1,000 and $10,000, at 0.18 basis points. But its costs rose quickly with size, from 0.36 basis points at $100,000 to more than 9.94 basis points for a $1 million trade. Because of their fee structures, Ostium and TradeXYZ were the most expensive venues for smaller trades, at 5.32 basis points and 4.67 basis points.
Variational Swap rose much more slowly, from 0.26 basis points at $1,000 to 0.47 basis points at $1 million. Castle Labs says that made it 12 times cheaper than TradeXYZ at 5.74 basis points and nearly 21 times cheaper than Lighter at 9.94 basis points.
US500: lowest cost at every size in the sample
For US500, the report says Variational was the cheapest venue at every size, including $1,000 and $10,000, where its execution cost was 0.415 basis points compared with 0.433 basis points for Lighter.
The gap widened as size increased. At $1 million, the cost advantage expanded to 5x, with execution costs of $79 for Variational versus $395 for the comparison level cited in the report. TradeXYZ and Ostium came in at 5.84 basis points and 4.60 basis points.
XAG: silver still shows thinner depth
In silver, Variational was cheapest at $1,000 and $10,000, at 0.12 basis points and 0.38 basis points. Once trade size reached $100,000, however, its execution cost moved above Lighter and stayed higher at larger sizes.
Castle Labs gives one example: a $500,000 XAG order cost 5.14 basis points on Variational versus 4.31 basis points on Lighter, a gap of about 20%. The report says XAG is currently the shallowest of the listed swap markets and does not yet show the same smooth quoting pattern seen in other markets.
XAU: stronger for larger orders
Gold showed a pattern closer to US100 and US500. For smaller orders, Lighter remained the cheaper alternative, with opening costs of $0.05 and $0.60 for $1,000 and $10,000 trades, respectively.
At $100,000 and above, Variational moved ahead. Its execution cost was 0.68 basis points, 65% lower than Lighter. At $1 million, Variational stayed in front at 1.66 basis points. The next closest venue was Ostium at 4.63 basis points, followed by TradeXYZ at 6.54 basis points and Lighter at 8.74 basis points.
Across the four markets, Castle Labs concludes that Variational was the cheapest venue in most size buckets for the assets currently listed, while Lighter retained an edge in smaller tickets for products such as gold and US100.
What the model solves, and what it still has to prove
The report says RWA and TradFi-linked assets are still taking a larger share of on-chain perpetual activity. Demand from crypto-native users exists already, but the novelty of these assets and the accessibility gained from putting them on-chain do not mean execution quality is yet at the level needed to pull in large institutional flow.
For perpetual protocols, the balancing act remains the same: list attractive new markets while keeping enough liquidity in place for efficient execution. Standard perpetuals add another problem for RWA traders because funding rates are unpredictable and can change the economics of a position.
Castle Labs presents Variational’s swaps as a structure that addresses both points at once. Retail traders get more predictable carry and a clearer view of the true cost of holding exposure. Institutions, in the report’s view, get lower execution costs, more predictable financing and tighter alignment with the underlying market.
The report says swaps already account for more than 50% of Variational’s daily trading volume and more than $220 million in open interest. US100 is the main driver. As of Sept. 7, that market represented more than 50% of all swap volume and 30% of open interest.
Across the initial listed markets, funding data showed longs paying 4.6% to 5.7% annualized, while shorts were earning about 2.4% annualized.
Castle Labs also spells out the trade-off. By bypassing the need to bootstrap liquidity market by market, swaps can bring TradFi-level depth into an on-chain venue and let a derivatives protocol aggregate liquidity where it already exists, then settle the exposure transparently on-chain. But users rely less on a broad public order book and more on Variational’s pricing, hedging, risk management and its ability to keep RFQ quotes competitive across hundreds of markets.
The report’s conclusion is that execution quality remains the metric that matters most. In its numbers, a $1 million US100 trade could be executed for as little as $47. In silver, by contrast, lower market depth meant a $1 million trade could cost $787, about 20% more than on Lighter. Because Variational does not charge platform trading fees, Castle Labs says that fee structure lowers all-in cost further and helps make the venue one of the more cost-efficient places to trade TradFi markets on-chain.