Market movers

Parameters

Name	In	Type	Required	Description
direction	query	string	no	shortened or drifted. Omit for both.
min_move	query	number	no	Smallest move to include, as a ratio of the opening price. 0.25 is a quarter shorter or longer.
region	query	string	no	Restrict to one jurisdiction.
run_type	query	string	no	Restrict to one run type.
date_from	query	string	no	YYYY-MM-DD. Clamped to your plan's window.
date_to	query	string	no	YYYY-MM-DD. Clamped to your plan's window.

Request

curl https://api.apihorseracing.com/v1/market/movers \
  -H "X-API-Key: $AHR_KEY"

$ch = curl_init('https://api.apihorseracing.com/v1/market/movers');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER     => ['X-API-Key: ' . getenv('AHR_KEY')],
]);
$data = json_decode(curl_exec($ch), true)['data'];

const res = await fetch(
  'https://api.apihorseracing.com/v1/market/movers',
  { headers: { 'X-API-Key': process.env.AHR_KEY } }
);
const { meta, data } = await res.json();

import os, requests

r = requests.get(
    "https://api.apihorseracing.com/v1/market/movers",
    headers={"X-API-Key": os.environ["AHR_KEY"]},
).json()

Response

200 OK application/json harvested 8 days ago

{
    "meta": {
        "request_id": "6d16f0b3ce4b43c8",
        "data_as_of": "2026-09-12T05:10:27+00:00",
        "plan": "analyst",
        "window": "2017 → upcoming",
        "count": 3
    },
    "data": {
        "window": {
            "from": null,
            "to": null,
            "note": "The whole archive. Your plan sets no date limit."
        },
        "by_movement": [
            {
                "movement": "drifted",
                "runs": 238036,
                "priced": 238036,
                "first": 20197,
                "second": 23001,
                "third": 24628,
                "fourth": 25263,
                "win_pct": 0.0848,
                "top3_pct": 0.2849,
                "expected_wins": 19621.82,
                "a_e": 1.029,
                "a_e_range": [
                    1.015,
                    1.044
                ],
                "a_e_beats_market": true,
                "significant": true,
                "low_sample": false,
                "pl_1pt": -66141.76,
                "roi_pct": -27.79
            },
            {
                "movement": "drifted sharply",
                "runs": 166181,
                "priced": 166181,
                "first": 6538,
                "second": 8556,
                "third": 10956,
                "fourth": 13410,
                "win_pct": 0.0393,
                "top3_pct": 0.1568,
                "expected_wins": 6609.09,
                "a_e": 0.989,
                "a_e_range": [
                    0.965,
                    1.013
                ],
                "a_e_beats_market": false,
                "significant": false,
                "low_sample": false,
                "pl_1pt": -65830.21,
                "roi_pct": -39.61
            },
            "… 3 more"
        ],
        "examples": [
            {
                "race_id": "rc_37HG0ZZ",
                "horse_id": "hs_2P8EM42",
                "horse": "How About It",
                "course": "Southwell",
                "date": "2018-03-05",
                "opening": "9/1",
                "sp": "150/1",
                "drift": 14.1,
                "position": 4
            },
            {
                "race_id": "rc_1QGF7XR",
                "horse_id": "hs_5GG8NB",
                "horse": "Jour D'orage",
                "course": "Worcester",
                "date": "2024-09-27",
                "opening": "200/11",
                "sp": "250/1",
                "drift": 12.0853,
                "position": 8
            },
            "… 1 more"
        ],
        "note": "Movement is starting price against opening price. Only runners whose opening price was published."
    }
}

A real response from /v1/market/movers?limit=3, captured by calling the live API rather than written by hand.

Response fields

Each field is described once and rendered on every endpoint that returns it, so the wording cannot drift between pages.

Field	Type	What it is
window	string	How far back and forward that plan can read.
runs	integer	Rides in the slice, priced or not.
priced	integer	Rides carrying a starting price. A/E and the profit figures use these; runs is the wider count.
first	integer	Wins.
second	integer	Seconds. Positions are returned separately so you apply your own place terms.
third	integer	Thirds.
fourth	integer	Fourths.
win_pct	number	Wins over runs. The number everyone quotes and the one that tells you least.
top3_pct	number	First, second or third over runs. Not a place strike rate; place terms vary.
expected_wins	number	Wins the market implied, summed over the slice.
a_e	number	Actual wins over expected. Above 1.00 means winning more often than the prices said.
a_e_range	array	Ninety five percent interval on A/E. If it spans 1.00 the figure is not evidence of anything.
a_e_beats_market	boolean	True only where the whole interval sits above 1.00.
significant	boolean	Whether the interval excludes 1.00 in either direction.
low_sample	boolean	Fewer than five expected wins. Treat A/E as noise.
pl_1pt	number	One point on every runner, settled at starting price.
roi_pct	number	Level stakes return. Backing everything loses more than the book margin, because equal stakes overweight the longshots.
race_id	string	Opaque race identifier. Stable, and safe to store.
horse_id	string	Opaque horse identifier.
horse	string	Horse name.
course	string	Course name.
date	date	Race date, YYYY-MM-DD.
opening	string	The price the runner opened at, where published.
sp	string	Starting price, fractional, as returned.
drift	number	Starting price against opening, as a ratio. Positive drifted, negative shortened.
position	integer	Finishing position. Null means the runner did not complete or was not published below the placings.

What varies by jurisdiction

Price movement is an opening price, not a full series

The source publishes no odds history on a settled race, only an opening price and any prices touched. About one runner in five carries one. price_path.source tells you which kind you have on every runner, so you never have to infer it.

Not every jurisdiction publishes a full finishing order

America publishes the placings and nothing below them, so position is null for most of the field. Britain, Ireland, France and South Africa carry a position for the great majority of runners. /v1/countries returns the current figure for each.

Errors this endpoint returns

Code	Status	When
unauthorized	401	No key, or one we do not recognise. Check the header name and that the key has not been rotated from your account page.
upgrade_required	403	The endpoint returns computed statistics and your plan does not include them. The body names every plan that does reach it, so you never have to look it up.
invalid_param	422	A date that is not YYYY-MM-DD, a by= dimension we do not have, or a cursor that did not come from us. The message names the parameter.
rate_limited	429	Past your per-minute rate. Retry-After is set, and X-RateLimit-Remaining tells you where you stand on every successful response too.
server_error	500	Ours, not yours. Every response carries a request_id; quote it and we can find the exact request.

Run it live

A real request from your browser straight to api.apihorseracing.com with your own key. Nothing is proxied and nothing is logged by this page.

Your API key

Remembered in this browser so you do not paste it on every page.

direction optional

min_move optional

region optional

run_type optional

date_from optional

date_to optional

What this is for

Whether money moving before the off tells you anything, measured across every runner that carries an opening price. Movers are grouped by how far they moved and in which direction, each band with a full statistics block.

The question is old and the folklore is confident: a horse that shortens is fancied and a drifter is not. This is the endpoint that decides whether that survives a confidence interval.

Two things limit it, and both should be understood before you read a result. Price movement exists only where the source published an opening price, which in this archive means Britain on about 59% of runners and Ireland on about 52%, and essentially nowhere else. And the movement is opening to starting price, not a full series, so a horse that shortened and drifted back looks like it never moved.

Both facts are on every runner in price_path.source, and this endpoint only considers runners where a real opening price exists rather than treating an absent one as no movement.

Common uses

Testing the folklore

direction=shortened with a min_move, over as much of the archive as your plan reaches. Read the interval.

Building a feature

If a band does show a genuine effect, the A/E is directly usable as a weight, and it already accounts for the price.

Deciding whether it is worth the trouble

The coverage limitation means any model using this only works on British and Irish racing. Better to know that first.

Available on