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Worked examples, in AI in Markets

Financial Document Token Estimator: Examples

The tokenization difference between providers matters at document scale. Anthropic counts roughly 3.5 characters per token; OpenAI and Google count about 4, so the same 10-K body of 72,000 characters is 20,571 tokens for Claude and 18,000 for GPT and Gemini. These scenarios fix a 10-K body and 2,000-token output, then show how that gap affects per-filing cost across providers. One-pass cost reads the filing once; synthesis re-ingests it with peer filings for a comparative analysis. List rates, no caching.

4 examples. Published May 26, 2026. By AI Fin Hub Research.

Worked examples

See the inputs and outcome together

Each scenario keeps the starting point, the outcome, and the actual lesson in one place so the page reads like a decision notebook, not a data dump.

  1. 1

    One-pass 10-K on a cheap model

    Reading a single 10-K body once on Claude Haiku 4.5 to extract a summary. The standard first-pass extraction job.

    20,571 input tokens, one-pass cost $0.0306, fits in context.

    Document

    10-K body (~72K chars)

    Output tokens

    2,000

    Peers

    1

    Model

    Claude Haiku 4.5

    A full 10-K reads for three cents on Haiku. The input dominates at $0.0206 because the filing is long and the output is short. For high-volume extraction this is the right tier; the filing comfortably fits the context window.

  2. 2

    Same filing, flagship model

    The identical one-pass read on Claude Fable 5.1, the choice when extraction accuracy on dense financials matters.

    20,571 input tokens, one-pass cost $0.3057 on Claude Fable 5.1, Anthropic's flagship, fits in context.

    Document

    10-K body (~72K chars)

    Output tokens

    2,000

    Peers

    1

    Model

    Claude Fable 5.1

    Fable 5.1 is ten times Haiku at $0.306 per filing, the ratio of their input and output prices since the token count is identical. The decision is quality against roughly 28 cents per filing, not a context or capability limit.

  3. 3

    Tokenizer difference on the same document

    Reading the same 10-K on GPT-5.5, which tokenizes at about 4 characters per token instead of Claude's 3.5.

    18,000 input tokens, one-pass cost $0.15, fits in context.

    Document

    10-K body (~72K chars)

    Output tokens

    2,000

    Peers

    1

    Model

    GPT-5.5

    GPT counts 18,000 tokens for the same filing that costs Claude 20,571, because its tokenizer packs more characters per token. The tokenizer alone gives a 12 percent token discount before any price difference; comparing models on price per filing, not price per token, is the only fair comparison.

  4. 4

    Five-peer synthesis

    A comparative analysis that ingests the target filing alongside five peer 10-Ks on Claude Haiku 4.5, then writes a synthesis. The realistic competitive-analysis workload.

    Synthesis input 123,426 tokens, synthesis cost $0.1334 (versus $0.0306 one-pass).

    Document

    10-K body (~72K chars)

    Output tokens

    2,000

    Peers

    5

    Model

    Claude Haiku 4.5

    Adding five peers multiplies the input six-fold (20.6K to 123K tokens) and roughly quadruples the cost to $0.133 — still cheap but no longer trivial. Multi-filing synthesis is where input volume, and therefore context window, starts to matter for model choice.

Patterns

Input tokens dominate filing-analysis cost because filings are long and outputs are short.
Anthropic models count about 3.5 characters per token versus 4 for OpenAI and Google, so the same filing is more tokens on Claude.
Compare models on cost per filing, not cost per token, to avoid tokenizer bias.
Multi-filing synthesis multiplies input volume, which is when the context window becomes a real constraint on model choice.

Run the numbers next

  • Generators SEC Filing Chunk Optimizer

    Pick a filing archetype, tune chunk size and overlap, and see chunk count, embedding cost, and structural-boundary warnings across three chunking strategies.

  • Calculators Earnings-Call Summarization Cost Calculator

    LLM cost per stock per quarter to summarize earnings transcripts across Sonnet, Opus, GPT-5.5, Gemini 2.5 Pro/Flash. Cache-hit-rate aware. Snapshot pricing.

Sources

  1. Anthropic API Pricing , Anthropic (2026)
  2. EDGAR Full-Text Search and Filing Access , U.S. Securities and Exchange Commission

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