A 6-year study of topological anomaly detection on Ethereum by Matan Prasma and Uri Yacobi Keller analyzing structural network shifts from 2020 to 2025.

When capital moves rapidly, when automated keeper bots compete for liquidation rights, or when institutions rebalance during macro shocks, the structural geometry of blockchain transaction graphs changes before prices or transaction counts reflect the shift.
In research led by mathematicians Matan Prasma (@KanExtension) and Uri Yacobi Keller (@urihamster) on ethresear.ch and documented in their open-source repository, researchers analyzed 2,191 consecutive days of Ethereum transaction history (2020-2025) using Topological Data Analysis (TDA).
By converting daily transaction flows into multi-dimensional spatial shapes and calculating their 1-Wasserstein geometric distance, their model flagged 86 major structural anomalies. When cross-referenced against historical events, 73 out of 86 (84.9%) aligned with real-world shocks, frequently serving as an early-warning signal days before public headlines.
This analysis synthesizes data from 10 primary sources to explore how high-dimensional geometry provides new insight into blockchain analytics, protocol risk management, and market intelligence.
Traditional blockchain analytics rely on scalar aggregates: Total Value Locked (TVL), daily active addresses, transaction throughput (TPS), or gas consumption.
However, scalar metrics count how much activity occurred, but cannot describe how that activity was structurally distributed across the network.
Consider two scenarios:
Both events might register identical gas usage ($10M) and transaction volume ($500M). Yet Event 1 represents organic retail flow, whereas Event 2 represents a tightly coupled liquidation loop during protocol stress.
As demonstrated in research by Ofori-Boateng et al. (2021), scalar metrics cannot differentiate between these states. Topological Data Analysis maps the spatial geometry of the underlying transaction graph to reveal these structural differences.
To convert daily Ethereum transactions into a structural signal, Prasma and Keller constructed a four-stage topological pipeline.
The researchers partitioned all Ethereum transactions into four disjoint operational layers based on calldata payload size and transaction type:
highInput (Calldata >= 500 bytes, 0 ETH value): Complex smart contract executions and factory deployments. This is the liquidation and crash layer, capturing automated keeper bot races, flash loan exploits, and complex smart contract interactions.medInput (Calldata 100-499 bytes, 0 ETH value): Mid-level contract calls. This is the DeFi operational layer, tracking DEX routing, yield rebalancing, and protocol liquidity adjustments.nonFactory (Calldata 1-99 bytes, 0 ETH value): Simple contract interactions. This is the institutional and custody layer, recording multi-sig wallet operations, ETF custodian movements, and governance voting.simple_txs (Value > 0 ETH): Plain ETH transfers without calldata. This is the retail and macro layer, capturing direct exchange deposits, withdrawals, and macroeconomic portfolio shifts.For each layer-day:
A Vietoris-Rips filtration places an expanding metric ball of radius $r \in [0, 1]$ around every address:
The birth radius ($r_{\text{birth}}$) and death radius ($r_{\text{death}}$) of every topological feature are plotted on a 2D Persistence Diagram. Features that persist across wide radius ranges represent true structural architecture, whereas short-lived features represent random transaction noise.
To measure day-over-day structural distortion, the pipeline calculates the 1-Wasserstein distance between consecutive daily persistence diagrams:
$$W_1(D_{t}, D_{t-1}) = \inf_{\gamma} \sum_{x \in D_{t}} |x - \gamma(x)|_1$$
This generates a daily metric for each layer measuring structural shift relative to the previous day.
Passing the daily Wasserstein metric through Seasonal Hybrid ESD (S-ESD) anomaly detection shows how different market shocks manifest in distinct topological layers.
highInput layer registered its highest single-day spike of 2020 on the exact same day ($z = 5.2$, 100th percentile).highInput topology.medInput layer fired two days later on February 26 ($z = 5.1$, 100th percentile).medInput (which tracks protocol-level rebalancing) captured the capital flight.medInput layer fired three days prior on June 9 ($z = 4.8$).medInput detected capital flight prior to the official freeze.medInput layer fired the following day on February 22 ($z = 5.1$, 99.9th percentile).medInput.Using global offline change-point detection (ruptures L2 cost optimization), the algorithm partitioned six years of data into seven distinct structural regimes without inspecting news, social media, or price charts:
| Regime Breakpoint | Nearest Real-World Catalyst | Primary Structural Shift |
|---|---|---|
| September 19, 2020 | Peak of DeFi Summer Yield Farming | Transition from liquidity mining frenzy to protocol consolidation |
| September 4, 2022 | 11 Days Before The Ethereum Merge | MEV searcher and validator repositioning prior to PoS migration |
| June 16, 2023 | 1 Day After BlackRock Spot BTC ETF Filing | Institutional re-rating of digital asset market infrastructure |
| October 25, 2023 | Start of Spot BTC ETF Rally | BTC breaks $35k; ETH breaks $2,000; liquidity expands |
| January 23, 2024 | Settlement of Spot BTC ETF Trading | GBTC outflow volatility settles into steady institutional inflows |
| January 29, 2025 | DeepSeek AI Market Shock | Nvidia drops 17%; global tech risk-off rotation impacts crypto |
The study's primary structural insight is Layer Rotation - the shift in which transaction layers trigger anomalies over time:
nonFactory layer dominated as ETF custodians (Coinbase Custody), institutional multi-sigs, and corporate treasuries executed direct smart contract interactions.simple_txs) dominated anomaly counts, reflecting sensitivity to US Federal Reserve policy, Treasury yields, and global technology equity shifts.Can topological anomalies predict future price volatility?
In a follow-up experiment documented in the Simplex-TDA Predictive Validation Repository, researchers combined rolling TDA topological descriptors with standard financial indicators to predict 7-day-ahead elevated volatility:
highInput Wasserstein distance monitoring to adjust collateral factors dynamically before liquidation cascades trigger.medInput structural loops to detect unauthorized cold-storage fund laundering in real time.Explore more guides and career playbooks