Our journey begins by zooming out and asking, "why are centralized perpetuals exchanges so much more successful than decentralized ones?"
One aspect overlooked by 2020s era perps protocols is that centralized exchanges offer lending facilities to market makers and large traders
Such lending facilities:
- Improve capital efficiency for trading ✅
- Can lead to collusion between the exchange and particular market makers if they get preferential terms (e.g. Alameda) ❌
BUT DeFi lending protocols ameliorate the risk of this!
Q: Can DeFi lending primitives build a more capital efficient perpetuals exchange?
First stab was @GMX_IO v1, which introduced the GLP pool to facilitate perps trades
One can view GLP as an "application-specific lending protocol": it lends pool assets to perpetuals traders
The flow is the following:
- Users who want yield deposit multiple assets into the pool
- Their assets are lent out to collateralize perps positions
e.g. Perps user opens up a 5x long position; user provides 1x collateral and the pool lends out the remaining 4x (+ charges a fee)
The loan is closed when either: 1. User pays back accrued fees and is returned their collateral 2. User is liquidated, returning pool's assets back
Unlike other DeFi lending, there is no discount/bonus paid to liquidate the position — collateral simply goes back to the pool
This is the sense that these loans are "application-specific" — lending protocol knows exactly *where* the borrowed assets are and can reclaim *exactly* what was lent out upon liquidation
Intuition: Risk/return of such loans should be way better than other forms of DeFi lending
TradFi analog: 'demand loans' to a market maker — often brokers or banks will do short-term loans to market makers so that they don't have to close open positions to quote on new markets (but are callable)
That's why we call such pools 'Perpetual Demand Lending Pools' (PDLPs)
How big are these markets?
The overall PDLP market size is ~$2.5B and has generated ~$897.93M in fees over the last 12 months, creating over 35%+ yields sustainably from trading fees (beating Bitcoin and Ethereum basis!)
@dYdX @HyperliquidX @JupiterExchange @GMX_IO Our paper does a few things: 1. Formalizes PDLPs in a manner general enough to include GLP, JLP, and @HyperliquidX's HLP, @dydx's MegaVault 2. What is funding rate arb in PDLPs? 2. Constructs a target-weight mechanism that describes how @GMX_IO/ @JupiterExchange's pool rebalance
3. Describes optimal arbitrage between the perps exchange and PDLP pool and shows that with high enough fees, E[PNL] > 0 for LPs and perpetuals traders 4. Describes LP losses in the pool that are analogous to @ciamac, et. al's LVR and shows that it is bounded in a way different to CFMMs
5. Lessened LP losses in PDLPs implies that pool shares are good collateral (c.f. @KaminoFinance / @DriftProtocol vaults) to borrow against (esp. when compared to CFMM shares) 6. Proves that these pools are easy to delta hedge via std. portfolio optimization
While there's a lot, let's go through them individually
== Formalizing PDLPs ==
PDLP users (like CFMMs) deposit 1+ assets in order to earn yield
PDLPs aim to stay near a target portfolio π* and provide creation-redemption incentives for arbitrageurs to keep the portfolio near the target
Depositors receive shares upon deposit
In HLP, the target portfolio is dynamically updated by an off-chain manager
In GLP and JLP, target portfolios are updated via creation-redemption arbitrage:
- Share Price < pool NAV: buy shares and redeem for pool assets
- Share Price > pool NAV: create shares from pool assets
You can see how well the pool share price tracks underlying asset price by looking at the difference between the market and "virtual" (i.e. the price if the NAV were distributed to the shares pro-rata) prices
== Funding Rate Arb ==
Can both LPs + perps traders be profitable? Surprisingly, yes! We formulate perpetuals arbitrage where a perpetuals trader tries to close a funding rate gap while generating PDLP fees
We show they both can be simultaneously profitable at high enough fees!
== Optimal Arbitrage + Weights ==
If virtual and market prices deviate, what is the **optimal** arbitrage to choose?
Unlike CFMMs like Uniswap, PDLPs allow users to redeem many different portfolios provided they satisfy some weak constraints — what's the optimal one to choose?
What does 'optimal' mean?
GLP + JLP define π* via a target weight — e.g., if the pool contains (SOL, WETH, USDC), the target weight might be (25%, 50%, 25%)
PDLP provides "discounts" if you move the pool closer to the target weights — arbitrageur wants to maximize the discount
How does the discount work?
Suppose a PDLP has 100 outstanding shares and when the pool moves closer to the target weight, I receive an 5% discount
This means if I take 20 shares worth of pool assets and try to mint 20 shares, I will receive 21 shares (the 5% bonus)
How do I perform the arbitrage?
There are many portfolios I could use to maximize the discount — all USDC, all SOL, 1/2 SOL + 1/2 USDC — how should I pick the right one?
View the discount as a function of the portfolio → pair of optimization problems for creation, redemption
We show that these optimization problems can be solved approximately using, e.g. gradient descent, *even if you don't know the discount function f*
This explains why these pools have (generally) had low tracking error even though arbitrageurs may not have known the optimal arb!
An aside: If you look at the original @GMX_IO V1 code base, you can see that they had the right intuition in a comment about using discounts as a PID-like method to staying near a target weight
This is weirdly the key to approximate the optimal arb
== Delta Hedging ==
There has been much written about how JLP seems to have "low delta" (e.g. low correlation to the assets held) which has led to the proliferation of leveraged and hedged JLP on @KaminoFinance and @DriftProtocol
We study this and show two things: 1. PDLPs have a bounded amount of extra delta rel. to the assets; this decreases as borrow fees go up 2. PDLPs are easy to delta hedge via Markowitz, improving the Sharpe ratio under broad conditions
Again, market intuition was (mainly) right!
The second result, in particular, is distinct from CFMMs — while there have been many attempts to hedge LVR/impermanent loss in CFMMs, none have been anywhere near as successful as delta-hedged JLP
Our results help explain when and why this is true for PDLPs but not CFMMs
The delta hedging result can be extended to study a question inspired by @GMX_IO V1 vs. V2: When should you use multiple pools vs. one big pool?
It turns out there's a nice Schur Complement condition for when to split pools (also: live V2 pools aren't optimally split)
tl;dr / recap: 1. PDLPs share similarities with CFMMs — creation-redemption arb and LVR — but they have low "wrong way" risk (they earn fees correlated to the direction of trade vs. CFMMs) 2. Allows us to bound their risk, partially explaining why JLP trades are so popular
But this opens a lot of new problems:
- How do we choose an optimal discount function F?
- How do we merge HLP-style pools (with single operators) with algorithmic weight mechanisms?
- Are there other types of application-specific loans in DeFi that could utilize this mechanism?
Thanks go out to a lot of folks for comments and feedback!
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On-chain DeFi intrinsically embeds collateral reqs — TradFi often misprices collateralized credit risk due to transparency
Pitch to (mid) economists: If crypto works… who fucking needs Basel III vs. a validated state root?
The idea that on-chain finance needs undercollateralized lending has been an analogy searching for a solution
DeFi is most successful when you have assets where *verifiable* guarantees on collateral are paramount to position value
But: undercollateralized == not verifiable
Why is this?
Dumb answer: Being undercollateralized opens the can of worms of the binomial American option model: a protocol has to figure out a stopping time for when you’re “too” undercollateralized and need to exit the market — MEV ruins this!
Are Liquid Restaking Tokens (LRTs) essential to restaking security and even risk mitigation, vs. being a source of systemic risk?
Surprisingly, yes! New paper w/ @malleshpai shows that smart allocation to AVSs is crucial for security against cascading failures
@ether_fi @RenzoProtocol @swellnetworkio @puffer_finance @KelpDAO @Eigenpiexyz_io First: What does this have to do with LRTs? They are the largest allocators + should be 'smart money' (due to economies of scale), with outsized impact on restaking security (see, e.g., )
Our paper builds off of the excellent work of @tim_roughgarden & Naveen that formulates cascade risk in combinatorial terms and argues that overcollateralization is needed for security — but we arrived at this via a circuitous path
Repeated arguments over economic security + issuance are a reminder Proof of Stake's threat model is completely and utterly broken — BFT models assume the worst economic attack is a double spend
Doesn't make sense when:
stablecoin supply + non staked TVL in DeFi > ETH staked
2024: We should analyze principal-agent relationships vs. reducing everything to double spends
Compute max profit for each principal-agent interaction (e.g. DS, oracle manipulation, etc.)
Example: Consider a rollup with a canonical bridge; there are many P-A interactions/attacks with different max profits: 1. DA layer down 💰💰💰💰 2. Sequencer censors execution 💰💰💰 3. Sequencer delays execution 💰💰 4. Sequencer sandwiches you / 'cheap' MEV attacks 💰
Three items are behind a wall and a solver is going to get one of them for you
Do you get a goat or a car, anon?
@malleshpai, @ks_kulk, @theo_diamandis and I show you that if solvers have to do more work to deliver the item to you, they're not going to show up to the auction
There’s been a lot of talk about `intents’. What are they?
Simply put: they're markets for transaction execution where third parties called solvers compete to satisfy user orders (and any constraints those orders come with)
Question: What are the principal-agent problems here?
tl;dr: We find broad conditions for oligopoly in intent markets
What is oligopoly here? 1. Fewer bidders, k, than the maximum possible, n, participate (i.e. k/n → 0 as n → ∞ or k=o(n)) 2. Users get *worse* prices even though the number of (potential) solvers increases!
While @artgobblers isn't exactly my cup of tea, the novel NFT auction mechanism ford is cool from an auction theory perspective— but is it incentive compatible (IC) for both buyers and sellers?
tl;dr: It is *not* IC but can be modified to be IC!
Quick recap: A gradual dutch auction (GDA) is a sequence of n auctions whose initial prices a_1 < ... < a_n are increasing but where the price of an auction decays as a_i * p(t) where p is non-increasing (e.g. p(t) = exp(-t) in the original paper)
Why would you use such an auction? If you have a series of NFT auctions (e.g. an edition, a daily @nounsdao auction, etc.), you want to incentivize users to pick bundles (e.g. any subset of items to buy) without forcing all of the supply on the market (reducing auction revenue)
1. Winning mechanisms in DeFi come from where you don’t expect (e.g. Uniswap vs. bad copies of TradFi products badly) 2. MEV-aware designs take advantage of FHE/ZK improve efficiency/costs 3. Treasury management isn’t just a meme