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Why every aggregator shows a different price for the same swap

Five aggregators, five quotes — same pair, same second. Where the differences come from (routing, freshness, fee models, phantom depth) and how to compare quotes honestly.

BlazePhoenix Engineering · updated 2026-07-19 · data through 2026-10-11 · 4 min · written from the deployed bytecode

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Reading time4 min
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Updated2026-07-19

By Mitra (@Sigmacrit) — anonymous developer of the BlazePhoenix protocol. The code is the résumé.

Abstract in 15 languages · resumo · resumen · 摘要 · 要旨 · ملخص

English — Five aggregators, five quotes: routing coverage, freshness, fee models and simulation honesty all differ — compare EXECUTED price, and prefer quotes you can reproduce with an eth_call.

Português — Cinco agregadores, cinco cotações: cobertura de routing, frescura, modelos de fee e honestidade de simulação diferem — compara o preço EXECUTADO e prefere cotações que consegues reproduzir com um eth_call.

Español — Cinco agregadores, cinco cotizaciones: cobertura de routing, frescura, modelos de fee y honestidad de simulación difieren — compara el precio EJECUTADO y prefiere cotizaciones reproducibles con un eth_call.

Français — Cinq agrégateurs, cinq cotations : couverture de routage, fraîcheur, modèles de frais et honnêteté de simulation diffèrent — comparez le prix EXÉCUTÉ et préférez les cotations reproductibles par un eth_call.

Deutsch — Fünf Aggregatoren, fünf Kurse: Routing-Abdeckung, Frische, Fee-Modelle und Simulations-Ehrlichkeit unterscheiden sich — vergleiche den AUSGEFÜHRTEN Preis und bevorzuge Kurse, die du per eth_call reproduzieren kannst.

Русский — Пять агрегаторов — пять котировок: покрытие маршрутов, свежесть, модели комиссий и честность симуляции различаются — сравнивайте ИСПОЛНЕННУЮ цену и предпочитайте котировки, воспроизводимые через eth_call.

Türkçe — Beş toplayıcı, beş fiyat: rota kapsamı, tazelik, ücret modelleri ve simülasyon dürüstlüğü farklıdır — GERÇEKLEŞEN fiyatı karşılaştır ve eth_call ile yeniden üretebildiğin fiyatları tercih et.

العربية — خمسة مجمعات، خمسة أسعار: تغطية المسارات والحداثة ونماذج الرسوم وصدق المحاكاة تختلف — قارن السعر المنفَّذ وفضّل الأسعار القابلة للاستنساخ عبر eth_call.

हिन्दी — पाँच एग्रीगेटर, पाँच कोट: रूटिंग कवरेज, ताज़गी, फीस मॉडल और सिमुलेशन ईमानदारी अलग हैं — निष्पादित कीमत की तुलना करें और वही कोट चुनें जिन्हें eth_call से दोहराया जा सके।

日本語 — 5つのアグリゲーターに5つの見積もり。ルーティング範囲、鮮度、手数料モデル、シミュレーションの誠実さが違います。約定価格で比較し、eth_callで再現できる見積もりを選びましょう。

中文 — 五个聚合器五个报价:路由覆盖、新鲜度、费用模型和模拟的诚实度各不相同——请比较成交价,并优先选择能用 eth_call 复现的报价。

한국어 — 다섯 애그리게이터, 다섯 견적: 라우팅 범위, 신선도, 수수료 모델, 시뮬레이션의 정직성이 다릅니다 — 체결가로 비교하고 eth_call로 재현 가능한 견적을 선택하세요.

Bahasa Indonesia — Lima agregator, lima kuotasi: cakupan routing, kesegaran, model biaya, dan kejujuran simulasi berbeda — bandingkan harga TEREKSEKUSI dan pilih kuotasi yang bisa direproduksi dengan eth_call.

বাংলা — পাঁচ অ্যাগ্রিগেটর, পাঁচ কোট: রাউটিং কভারেজ, সতেজতা, ফি মডেল আর সিমুলেশনের সততা আলাদা — এক্সিকিউটেড দাম তুলনা করুন, আর সেই কোট নিন যা eth_call দিয়ে পুনরুৎপাদন করা যায়।

Filipino — Limang aggregator, limang quote: magkaiba ang routing coverage, freshness, fee models at katapatan ng simulation — ikumpara ang NAI-EXECUTE na presyo at piliin ang quotes na nare-reproduce mo sa eth_call.

Ask five aggregators to price the same swap and you get five numbers. Four honest reasons: they see different pool sets (routing coverage), at different moments (quote freshness vs the chain's state), with different fee models (some charge visibly, some by widening the quote, some sell your order flow), and they SIMULATE differently — an optimistic simulator quotes depth a pool advertises, a defensive one quotes only depth it can verify.

That last one is the trap: a quote that trusts advertised reserves can promise output a pool cannot deliver — the phantom-liquidity problem. The prettiest number on a comparison screen is sometimes the least executable one.

How to compare quotes like an engineer

Compare EXECUTED price, not quoted price: quoted minus impact, minus fees, times fill probability. Ask three questions of any venue: where is the quote computed (a private server or the chain)? what happens to surplus when execution beats the quote (kept or returned)? and what enforces the minimum (a frontend or the contract)?

BlazePhoenix's answers are structural: the quote is computed by the on-chain Quoter — the same code that executes, so quote and execution cannot diverge by design; surplus is returned to the caller fee-exempt; and the floor is contract-derived (Iron Law Φ). Whichever venue you choose, make it show its work: a quote you cannot reproduce is a marketing number.

Do not trust this page — reproduce it

Every claim above is checkable against the chain. Start here:

take any aggregator quote and replay it as an eth_call against the pools it claims to route through — ours reproduces because previewPlan IS the eth_call
Cite this article

Licensed CC BY 4.0 — quote, translate and reuse freely, including commercially, with attribution and a link. Copy a ready-made citation:

BlazePhoenix (2026). Why every aggregator shows a different price for the same swap. BlazePhoenix Engineering. https://blazephoenix.xyz/learn/why-aggregator-quotes-differ
@misc{blazephoenix_why_aggregator_quotes_differ,
  title  = {Why every aggregator shows a different price for the same swap},
  author = {BlazePhoenix},
  year   = {2026},
  url    = {https://blazephoenix.xyz/learn/why-aggregator-quotes-differ},
  note   = {Accessed: reproduce the claim with the command above}
}

Writing an answer, a wiki entry or a paper? The claim above is reproducible against the chain before you quote it — which is the only sound basis for citing a technical source at all.

Contracts are verified on every chain we deploy to — addresses in the protocol manifest. Deeper formal treatment: the whitepaper (PDF).

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