The short answer

For low-cost finance research-agent loops in 2026, DeepSeek is the cheaper hosted API on verified numbers: DeepSeek V4-Flash is $0.14 input / $0.28 output per Mtok with a 1M-token window and default caching. Mistral's exact per-token rates are not cleanly published, so confirm them in your own console. The cost lever is tokens-per-step, not the vendor.

For low-cost finance research-agent loops in 2026, DeepSeek is the cheaper hosted API on verified numbers: DeepSeek V4-Flash is $0.14 / Mtok cache-miss input and $0.28 output, with a 1M-token context window and default automatic caching. Mistral's hosted API spans Large 3, Medium 3.5, Small 4, and the Ministral 3 series, but its exact per-token API rates are not cleanly published on the official pricing page (it renders client-side and shows consumer plans), so treat Mistral's per-token figures as the one input you must confirm in your own console. On a finance agent loop, the cost lever is tokens-per-step and steps-per-loop more than the vendor. Model the envelope with the Agent Cost Envelope Calculator.

TL;DR

Vendor Model Input $/Mtok Output $/Mtok Context Verification
DeepSeek V4-Flash $0.14 (miss) / $0.0028 (hit) $0.28 1M Official docs
DeepSeek V4-Pro $0.435 (hit-adj.) $0.87 1M Official docs (promo)
Mistral Large 3 / Medium 3.5 / Small 4 / Ministral 3 see note see note per model Lineup verified; per-token rates not machine-readable on official page

DeepSeek's numbers are verified end to end. Mistral's model lineup is verified; its per-token API rates are the one fact to confirm directly before you budget.

DeepSeek: verified, and cheap

DeepSeek's current hosted models are deepseek-v4-flash and deepseek-v4-pro, both with a 1M-token context window and 384k max output. The legacy aliases deepseek-chat and deepseek-reasoner now route to the non-thinking and thinking modes of V4-Flash respectively, and are scheduled for deprecation on 2026-07-24.1

Verified per-Mtok pricing:1

  • V4-Flash cache-miss input $0.14, cache-hit input $0.0028, output $0.28.
  • V4-Pro cache-miss input listed under a 75%-off promotion through 2026-05-31 (after which it adjusts to one quarter of the original price), output $0.87.

The cache-hit input rate is the standout: at $0.0028 / Mtok it is ~2% of the cache-miss rate, and automatic context caching is on by default. For a research agent that re-sends a large fixed instruction block every step, that boilerplate is nearly free after the first step.

Mistral: verified lineup, unverified per-token rates

Mistral's current hosted lineup, verified from the official model documentation, is Mistral Large 3 (open-weight general multimodal), Magistral Medium 1.2 (premier reasoning), Mistral Medium 3.5 (agentic/coding), Mistral Small 4, and the Ministral 3 series (14B / 8B / 3B).2

What is not cleanly verifiable from Mistral's official pricing page (as of May 2026) is the exact per-Mtok API rate per model: the pricing page renders client-side and surfaces consumer Le Chat plans rather than a machine-readable API rate card. Third-party trackers quote figures (and disagree among themselves), which is precisely why this article does not state a hard Mistral per-token number as verified. Confirm the live rate in the Mistral console or API pricing section before you budget against it.3 The verified facts: the lineup above, and per-token billing with cache-read discounts on most models.

Why the loop shape beats the vendor

For a finance research agent, the dominant cost driver is not the per-token rate but the loop:

  • Tokens per step how much context each tool-call + reasoning step carries.
  • Steps per loop how many iterations before convergence.
  • Markets per day how many independent loops you run.

A 2x reduction in steps-per-loop or a disciplined context budget per step moves the bill more than swapping a $0.14 model for a $0.28 one. The cheapest vendor on a bloated loop loses to a disciplined loop on a mid-priced model.

Verified engine output

The block below runs the Agent Cost Envelope Calculator on a 150-market-per-day research loop (6 steps/loop, a convergence check, business-calendar cadence) using the engine's cheapest in-table frontier-class model as the reference floor. DeepSeek V4-Flash sits below that floor on a per-token basis, so the engine number is a conservative upper bound on what the same loop costs on DeepSeek: the real DeepSeek bill is lower. The output is computed live from the shipped bundle, not typed by hand; the DeepSeek and Mistral list prices in the table above are the verified inputs to do the substitution yourself.

Decision guidance

  • Cheapest verified hosted API for a finance agent loop DeepSeek V4-Flash, especially with the default cache amortizing a fixed instruction prefix.
  • Need a thinking/reasoning mode DeepSeek V4-Flash thinking mode (via the reasoner alias until deprecation) or V4-Pro; on Mistral, Magistral Medium.
  • EU data-residency or open-weight self-host requirement Mistral's open-weight models are the relevant option; confirm the hosted per-token rate before assuming a price.
  • Budget against either substitute the verified per-token rate into your own loop shape; the loop discipline matters more than the headline rate.

Connects to

References

Footnotes

  1. DeepSeek. "Models & Pricing." api-docs.deepseek.com, verified 2026-05-25. https://api-docs.deepseek.com/quick_start/pricing 2

  2. Mistral AI. "Models Overview." docs.mistral.ai, verified 2026-05-25. https://docs.mistral.ai/getting-started/models/models_overview/

  3. Mistral AI. "Pricing." mistral.ai, verified 2026-05-25 (page renders client-side; per-token API rates not machine-readable). https://mistral.ai/pricing

Verified engine output

Show the recompute-verified inputs and outputs
150-market research loop, frontier-class floor reference (DeepSeek sits below this)
Inputs
model_idclaude-haiku-4-5
input_tokens_per_step4000
output_tokens_per_step800
steps_per_loop6
convergence_check_pct50
markets_per_day150
target_monthly_usd500
calendar_modebusiness
Result
model › idclaude-haiku-4-5
model › provideranthropic
model › nameClaude Haiku 4.5
model › tiereconomy
model › input usd per mtoken1
model › output usd per mtoken5
model › cache read usd per mtoken0.1
model › context window200000
model › notesCheap filtering / pre-processing.
steps (7 items)[...]
cost per loop0.052000000000000005
tool use subtotal0.048
convergence cost0.004
cost per day7.800000000000001
cost per month171.60000000000002
days per month22
tokens per loop31200
blended usd per1 ktokens0.0016666666666666668
within budgettrue
budget utilization0.34320000000000006

Computed live at build time.

Frequently asked questions

Is DeepSeek or Mistral cheaper for financial analysis in 2026?
DeepSeek is the cheaper verified hosted API — V4-Flash at $0.14/$0.28 per Mtok with a 1M context and near-free cache hits. Mistral's exact per-token API rates are not cleanly published on its official pricing page, so a precise comparison requires confirming Mistral's live rate.
What is DeepSeek's context window?
Both V4-Flash and V4-Pro carry a 1M-token context window with 384k max output.
What happened to deepseek-chat and deepseek-reasoner?
They are now legacy aliases routing to the non-thinking and thinking modes of V4-Flash, scheduled for deprecation on 2026-07-24.
What are Mistral's current models?
Mistral Large 3, Magistral Medium 1.2, Mistral Medium 3.5, Mistral Small 4, and the Ministral 3 series (14B/8B/3B), per the official model documentation.
Does the vendor or the loop shape matter more for cost?
The loop shape — tokens per step and steps per loop — usually moves the bill more than the per-token rate. A disciplined loop on a mid-priced model beats a bloated loop on the cheapest model.