Polymarket

Compare Synth predictions against Polymarket prices.

Daily Up/Down

Forecast Horizon: 24h

Endpoint:

GET /insights/polymarket/up-down/daily

Example Request

curl

curl "https://api.synthdata.co/insights/polymarket/up-down/daily?asset=BTC" \
  -H "Authorization: Apikey YOUR_API_KEY"

Response:

{
  "slug": "bitcoin-up-or-down-on-february-27",
  "start_price": 66806.69,
  "current_time": "2026-02-27T15:16:37+00:00",
  "current_price": 66102.10,
  "current_outcome": "Down",
  "synth_probability_up": 0.1078,
  "synth_outcome": "Down",
  "polymarket_probability_up": 0.125,
  "polymarket_outcome": "Down",
  "event_start_time": "2026-02-26T17:00:00+00:00",
  "event_end_time": "2026-02-27T17:00:00+00:00",
  "event_creation_time": "2026-02-25T17:09:48+00:00",
  "best_bid_price": 0.12,
  "best_ask_price": 0.13,
  "best_bid_size": 5.0,
  "best_ask_size": 456.0,
  "polymarket_last_trade_time": "2026-02-27T15:14:01+00:00",
  "polymarket_last_trade_price": 0.89,
  "polymarket_last_trade_outcome": "Down"
}

Hourly Up/Down

Forecast Horizon: 1h

Endpoint:

GET /insights/polymarket/up-down/hourly

Example Request

curl

curl "https://api.synthdata.co/insights/polymarket/up-down/hourly?asset=BTC" \
  -H "Authorization: Apikey YOUR_API_KEY"

Response:

{
  "slug": "bitcoin-up-or-down-february-27-10am-et",
  "start_price": 66176.05,
  "current_time": "2026-02-27T15:16:43+00:00",
  "current_price": 66102.10,
  "current_outcome": "Down",
  "synth_probability_up": 0.3925,
  "synth_outcome": "Down",
  "polymarket_probability_up": 0.635,
  "polymarket_outcome": "Up",
  "event_start_time": "2026-02-27T15:00:00+00:00",
  "event_end_time": "2026-02-27T16:00:00+00:00",
  "event_creation_time": "2026-02-25T15:02:38+00:00",
  "best_bid_price": 0.63,
  "best_ask_price": 0.64,
  "best_bid_size": 82.01,
  "best_ask_size": 135.0,
  "polymarket_last_trade_time": "2026-02-27T15:15:37+00:00",
  "polymarket_last_trade_price": 0.32,
  "polymarket_last_trade_outcome": "Down"
}

15-Minute Up/Down

Forecast Horizon: 1h

Assets: BTC, ETH, SOL

Endpoint:

GET /insights/polymarket/up-down/15min

Example Request

curl

curl "https://api.synthdata.co/insights/polymarket/up-down/15min?asset=BTC" \
  -H "Authorization: Apikey YOUR_API_KEY"

Response:

{
  "slug": "btc-updown-15m-1772204400",
  "start_price": 66176.05,
  "current_time": "2026-02-27T15:04:21+00:00",
  "current_price": 65936.60,
  "current_outcome": "Down",
  "synth_probability_up": 0.0969,
  "synth_outcome": "Down",
  "polymarket_probability_up": 0.475,
  "polymarket_outcome": "Down",
  "event_start_time": "2026-02-27T15:00:00+00:00",
  "event_end_time": "2026-02-27T15:15:00+00:00",
  "best_bid_price": 0.47,
  "best_ask_price": 0.48,
  "best_bid_size": 218.0,
  "best_ask_size": 445.47,
  "polymarket_last_trade_time": "2026-02-27T14:59:57+00:00",
  "polymarket_last_trade_price": 0.4582015,
  "polymarket_last_trade_outcome": "Down"
}

Price Range

Forecast Horizon: 24h

Endpoint:

GET /insights/polymarket/range

Response:

response.json

[
  {
    "title": "[90, 0, 92, 0]",
    "ref_prices": [90, 0, 92, 0],
    "current_price": 88862.66,
    "synth_probability": 0.0,
    "polymarket_probability": 0.053,
    "event_end_time": "2026-01-22T17:00:00+00:00"
  }
]

Example: Find Arbitrage

example.py

import requests

response = requests.get(
    "https://api.synthdata.co/insights/polymarket/up-down/daily",
    headers={"Authorization": "Apikey YOUR_API_KEY"},
    params={"asset": "BTC"}
)

data = response.json()
synth = data['synth_probability_up']
poly = data['polymarket_probability_up']
edge = synth - poly

if abs(edge) > 0.05:
    if edge > 0:
        print(f"BUY 'Up' on Polymarket - Synth says {synth:.1%} vs market {poly:.1%}")
    else:
        print(f"BUY 'Down' on Polymarket - Synth says {1-synth:.1%} vs market {1-poly:.1%}")