Pricing Engine: Weighted Averages & Outlier Filtering

Mobula’s pricing engine aggregates price data from hundreds of liquidity pools across multiple chains to compute a single, reliable USD price for every token. This guide explains the mathematics and algorithms behind accurate price discovery.

Why it matters: A token like WETH might trade at slightly different prices on Uniswap, Sushiswap, Curve, and 50 other DEXs. Our engine combines all these prices into one reliable value, filtering out manipulated pools and scams.

Overview: The Pricing Pipeline

Pool Data Collection → Mode Selection → Outlier Filtering → Weight Calculation → Weighted Average

Each step is critical for accuracy:

Pool Data Collection: Gather price, volume, reserve, and depth from all pools
Mode Selection: Choose between volume-based or reserve-based weighting
Outlier Filtering: Remove scam pools and manipulated prices
Weight Calculation: Apply stable multiplier and depth adjustments
Weighted Average: Compute final price

Step 1: Pool Data Collection

For each pool trading a token, we extract:

interface PoolWeight {
  price: number;           // Token's USD price in this pool
  normalizedVolume: number; // 24h volume (0 if below threshold)
  realVolume: number;      // Actual 24h volume for metrics
  reserve: number;         // Total liquidity (TVL)
  depthUp: number;         // Buy-side market depth
  depthDown: number;       // Sell-side market depth
}

Example: Token XYZ trading on 4 pools:

Pool	Price	Volume	Reserve	Paired With
Uniswap V3	$1.00	$5M	$10M	USDC
Sushiswap	$1.02	$2M	$4M	ETH
PancakeSwap	$0.98	$1M	$2M	USDT
ScamDEX	$0.10	$1K	$10K	ETH

Step 2: Mode Selection

The engine chooses a weighting strategy based on available data:

const computeMode: 'volume' | 'reserve' = 
  totalNormalizedVolume > 0 ? 'volume' : 'reserve';

Condition	Mode	Weight Source	Use Case
Any pool has volume > 0	`volume`	normalizedVolume	Active tokens
All pools have volume = 0	`reserve`	reserve (TVL)	New/inactive tokens

Reserve mode is a fallback for newly listed or low-activity tokens where volume data isn’t reliable.

Step 3: Outlier Filtering (Two-Phase Median)

This is the most critical step. It removes:

Scam pools with manipulated prices
Stale pools with outdated prices
Low-liquidity pools with extreme slippage

Phase 1: Weighted Median Calculation

// Sort prices by value
const sortedPrices = prices.sort((a, b) => a - b);

// Find weighted median
let accumulatedWeight = 0;
let medianPrice = 0;

for (let i = 0; i < sortedPrices.length; i++) {
  accumulatedWeight += weights[i];
  if (accumulatedWeight >= totalWeight / 2) {
    medianPrice = sortedPrices[i];
    break;
  }
}

Phase 2: Log-Space Deviation Check

// Calculate deviation in log space (handles multiplicative differences)
const logPrice = Math.log(price);
const logMedian = Math.log(medianPrice);
const deviation = Math.abs(logPrice - logMedian);

// Threshold: 10% in volume mode, 15% in reserve mode (more permissive)
const threshold = computeMode === 'reserve' 
  ? BASE_THRESHOLD * 1.5 
  : BASE_THRESHOLD;

const isOutlier = deviation > threshold;

Why log space?

A price of $0.50 vs$ 1.00 (50% lower) should be treated the same as $2.00 vs$ 1.00 (100% higher)
Log space makes these symmetric: log(0.5) = -0.69, log(2) = 0.69

Filtering Result

After filtering our example:

Pool	Price	Status
Uniswap V3	$1.00	✅ Valid (near median)
Sushiswap	$1.02	✅ Valid (2% deviation)
PancakeSwap	$0.98	✅ Valid (2% deviation)
ScamDEX	$0.10	❌ Outlier (90% deviation)

Step 4: Weight Calculation

Stable Multiplier

Pools paired with stablecoins provide more reliable pricing than pools paired with volatile assets:

const STABLE_MULTIPLIER = 3;

let weight = normalizedVolume;

// Non-stable pairs get boosted weight to compensate for their
// typically lower volume but higher price accuracy
if (!baseQuote.isStableCoin({ chainId, address })) {
  weight *= STABLE_MULTIPLIER;
}

Why boost non-stable pairs?

Stable-paired pools (USDC, USDT) give direct USD prices
ETH-paired pools require ETH→USD conversion, introducing small errors
But ETH pairs often have MORE volume, so we boost stable pairs to balance

Depth Weighting (Optional)

When ponderWithDepth = true:

if (ponderWithDepth) {
  const depth = depthUp + depthDown;
  weight = depth > 0 ? normalizedVolume * depth : normalizedVolume;
}

This prioritizes pools where large trades can execute with minimal slippage.

Final Weights Example

Pool	Volume	Paired	Multiplier	Final Weight
Uniswap V3	$5M	USDC	×1	$5M
Sushiswap	$2M	ETH	×3	$6M
PancakeSwap	$1M	USDT	×1	$1M

Step 5: Weighted Average

The final price is computed as:

function computeWeightedMean(
  prices: number[], 
  weights: number[], 
  count: number
): [number, number] {
  let weightedSum = 0;
  let totalWeight = 0;
  
  for (let i = 0; i < count; i++) {
    weightedSum += prices[i] * weights[i];
    totalWeight += weights[i];
  }
  
  const price = weightedSum / totalWeight;
  return [price, totalWeight];
}

Example Calculation

numerator = (1.00 × 5M) + (1.02 × 6M) + (0.98 × 1M)
          = 5M + 6.12M + 0.98M
          = 12.1M

denominator = 5M + 6M + 1M = 12M

finalPrice = 12.1M / 12M = $1.0083

Asset-Level Pricing

For tokens deployed on multiple chains, we aggregate token prices into a single asset price.

Why Aggregate?

The same token can have different prices on different chains due to:

Bridge delays and costs
Chain-specific liquidity
Arbitrage opportunities

Aggregation Algorithm

computeAssetPrice(tokenResults: Map<SelectorStr, TokenResult>) {
  const count = tokenResults.size;
  if (count === 0) return null;
  
  // Determine weighting mode
  let totalVolume = 0;
  let totalReserve = 0;
  for (const data of tokenResults.values()) {
    totalVolume += data.volume;
    totalReserve += data.reserve;
  }
  
  const useVolume = totalVolume > 0;
  const total = useVolume ? totalVolume : totalReserve;
  
  // Filter by threshold (1% minimum share)
  const VOLUME_THRESHOLD = 0.01;
  const validTokens = [];
  
  for (const data of tokenResults.values()) {
    const share = useVolume 
      ? data.volume / total 
      : data.reserve / total;
    
    if (share >= VOLUME_THRESHOLD) {
      validTokens.push(data);
    }
  }
  
  // Weighted average
  return computeWeightedMean(
    validTokens.map(t => t.price),
    validTokens.map(t => useVolume ? t.volume : t.reserve),
    validTokens.length
  );
}

Example: USDT Asset Price

Chain	Token Price	Volume	Share
Ethereum	$1.001	$500M	89.3%
BSC	$0.999	$50M	8.9%
Polygon	$1.000	$10M	1.8%
Obscure Chain	$0.50	$100	0.00002% ← Filtered

assetPrice = (1.001×500M + 0.999×50M + 1.000×10M) / 560M
           = $1.0008

Outlier Detection for Assets

When aggregating across chains, we also filter token-level outliers:

const ASSET_TOKEN_OUTLIER_THRESHOLD = 2.0; // 200% deviation

for (const token of filteredTokens) {
  const priceDeviation = Math.abs(token.price - assetPrice) / assetPrice;
  
  if (priceDeviation > ASSET_TOKEN_OUTLIER_THRESHOLD) {
    outlierTokens.push(token);
    continue;
  }
  validTokens.push(token);
}

// Re-compute price without outliers
if (outlierTokens.length > 0 && validTokens.length > 0) {
  return computeWeightedMean(validTokens);
}

Performance Optimizations

Pre-allocated Buffers

// Avoid allocations in hot path
private readonly priceBuffer: Float64Array;
private readonly weightBuffer: Float64Array;
private readonly logPriceBuffer: Float64Array;

constructor(maxPoolsPerToken = 256) {
  this.priceBuffer = new Float64Array(maxPoolsPerToken);
  this.weightBuffer = new Float64Array(maxPoolsPerToken);
  this.logPriceBuffer = new Float64Array(maxPoolsPerToken);
}

Selector Caching

private readonly selectorCache: Map<SelectorStr, { chainId: ChainId; address: string }>;

private parseSelectorCached(selector: SelectorStr) {
  let cached = this.selectorCache.get(selector);
  if (!cached) {
    cached = parseSelector(selector);
    if (this.selectorCache.size < 1000) {
      this.selectorCache.set(selector, cached);
    }
  }
  return cached;
}

Validation & Safety

Price Bounds

const INSANE_PRICE_THRESHOLD = 1e15; // $1 quadrillion

isValidPrice(price: number): boolean {
  return price > 0 && 
         price < INSANE_PRICE_THRESHOLD && 
         Number.isFinite(price);
}

Minimum Valid Prices

const MIN_VALID_PRICES = 2;

// Require at least 2 valid pools for reliable pricing
if (validIndices.length < MIN_VALID_PRICES) {
  return null;
}

API Access

Token Price

# Get price for Fartcoin on Solana
curl -X GET "https://demo-api.mobula.io/api/2/token/details?blockchain=solana&address=9BB6NFEcjBCtnNLFko2FqVQBq8HHM13kCyYcdQbgpump" \
  -H "Authorization: YOUR_API_KEY"

# Get price for Wojak on Solana
curl -X GET "https://demo-api.mobula.io/api/2/token/details?blockchain=solana&address=8J69rbLTzWWgUJziFY8jeu5tDwEPBwUz4pKBMr5rpump" \
  -H "Authorization: YOUR_API_KEY"

# Get WETH price on Ethereum
curl -X GET "https://demo-api.mobula.io/api/2/token/details?blockchain=ethereum&address=0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2" \
  -H "Authorization: YOUR_API_KEY"

Response includes:

{
  "data": {
    "priceUSD": 0.0234,
    "volume24hUSD": 890000.50,
    "liquidityUSD": 250000.75,
    "priceChange24hPercentage": -5.8,
    "approximateReserveUSD": 125000.50
  }
}

Real-Time Updates

For real-time price updates, use the WSS Token Details WebSocket stream.

Summary

Step	Purpose	Key Technique
Data Collection	Gather all pool data	Multi-DEX aggregation
Mode Selection	Choose weighting strategy	Volume vs Reserve fallback
Outlier Filtering	Remove manipulated prices	Two-phase log-space median
Weight Calculation	Prioritize reliable sources	Stable multiplier (×3)
Weighted Average	Compute final price	Σ(price × weight) / Σweight

The result: accurate, manipulation-resistant prices updated in real-time across 100+ blockchains.

Memecoin

Spot Markets

Pricing Engine Deep Dive

Pricing Engine: Weighted Averages & Outlier Filtering

Overview: The Pricing Pipeline

Step 1: Pool Data Collection

Step 2: Mode Selection

Step 3: Outlier Filtering (Two-Phase Median)

Phase 1: Weighted Median Calculation

Phase 2: Log-Space Deviation Check

Filtering Result

Step 4: Weight Calculation

Stable Multiplier

Depth Weighting (Optional)

Final Weights Example

Step 5: Weighted Average

Example Calculation

Asset-Level Pricing

Why Aggregate?

Aggregation Algorithm

Example: USDT Asset Price

Outlier Detection for Assets

Performance Optimizations

Pre-allocated Buffers

Selector Caching

Validation & Safety

Price Bounds

Minimum Valid Prices

API Access

Token Price

Real-Time Updates

Summary

Memecoin

Spot Markets

​Pricing Engine: Weighted Averages & Outlier Filtering

​Overview: The Pricing Pipeline

​Step 1: Pool Data Collection

​Step 2: Mode Selection

​Step 3: Outlier Filtering (Two-Phase Median)

​Phase 1: Weighted Median Calculation

​Phase 2: Log-Space Deviation Check

​Filtering Result

​Step 4: Weight Calculation

​Stable Multiplier

​Depth Weighting (Optional)

​Final Weights Example

​Step 5: Weighted Average

​Example Calculation

​Asset-Level Pricing

​Why Aggregate?

​Aggregation Algorithm

​Example: USDT Asset Price

​Outlier Detection for Assets

​Performance Optimizations

​Pre-allocated Buffers

​Selector Caching

​Validation & Safety

​Price Bounds

​Minimum Valid Prices

​API Access

​Token Price

​Real-Time Updates

​Summary

Pricing Engine: Weighted Averages & Outlier Filtering

Overview: The Pricing Pipeline

Step 1: Pool Data Collection

Step 2: Mode Selection

Step 3: Outlier Filtering (Two-Phase Median)

Phase 1: Weighted Median Calculation

Phase 2: Log-Space Deviation Check

Filtering Result

Step 4: Weight Calculation

Stable Multiplier

Depth Weighting (Optional)

Final Weights Example

Step 5: Weighted Average

Example Calculation

Asset-Level Pricing

Why Aggregate?

Aggregation Algorithm

Example: USDT Asset Price

Outlier Detection for Assets

Performance Optimizations

Pre-allocated Buffers

Selector Caching

Validation & Safety

Price Bounds

Minimum Valid Prices

API Access

Token Price

Real-Time Updates

Summary