API Endpoint

Average Cost Basis

Calculate weighted average cost basis when adding to a position.

Endpoint

POST https://likeoptions.com/api/v1/calculate/avgcost

Also supports GET with query parameters.

Parameters

Parameter	Type	Default	Description
`existingShares`	number	—	Existing shares owned
`existingAvgCost`	number	—	Existing average cost per share ($)
`newShares`	number	—	New shares purchased
`newPrice`	number	—	New purchase price per share ($)

Request Examples

POST (JSON body)

curl -X POST https://likeoptions.com/api/v1/calculate/avgcost \
  -H "Content-Type: application/json" \
  -d '{"existingShares": 100000, "existingAvgCost": 50000, "newShares": 6}'

GET (query parameters)

curl "https://likeoptions.com/api/v1/calculate/avgcost?existingShares=100000&existingAvgCost=50000&newShares=6"

Response

{
  "kind": "avgcost",
  "result": {
    "primary": 1234.56,
    "secondary": [
      { "label": "Example metric", "value": 100, "format": "money" },
      { "label": "Example percent", "value": 5.5, "format": "percent" }
    ]
  }
}

When to Use

Calculate tax basis
Track cost basis
Plan averaging-down strategies

Error Handling

400 Bad Request — Invalid input parameters or missing required fields
404 Not Found — Unknown calculator kind
429 Too Many Requests — Rate limit exceeded (120 req/hour per IP)
413 Payload Too Large — Request body exceeds 16 KB

Related Endpoints

Stock Profit/Loss

View request examples in JavaScript, Python, cURL, and more →