Ticks, pips, and subcents

TICK_SPAN = 10_000  # $1

def cents_to_tick(cents: float) -> int:
    """47.00 → 4700. 96.10 → 9610."""
    return int(round(cents * 100))

def tick_to_cents(tick: int) -> float:
    return tick / 100.0

{
  "type": "tick_size",
  "market_id": 71,
  "policy": "narrow",
  "mode": "cent",
  "tick_step": 10,
  "wing_lo": 400,
  "wing_hi": 9600
}

def on_grid(tick: int, ts: dict) -> bool:
    if tick < 1 or tick >= 10_000:
        return False
    step = int(ts["tick_step"])
    lo, hi = int(ts["wing_lo"]), int(ts["wing_hi"])
    if ts.get("policy") == "broadband":
        return step != 0 and tick % step == 0
    if tick < lo or tick > hi:
        return step != 0 and tick % step == 0
    return tick % 100 == 0

best_yes_bid = book["yes"][0][0]
best_yes_ask = 10_000 - book["no"][0][0]

Q(p) = p · (10000 − p)
fee  = ceil(rate · qty · Q / 10^10)

from omnibook import Client
from omnibook.ticks import TICK_SPAN, cents_to_tick, on_grid

with Client(api_key="…", api_secret="…") as client:
    markets = client.get_markets(status="trading")
    m = next(x for x in markets["markets"] if x["status"] == "trading")
    book = client.get_orderbook(m["market_id"])
    tick = cents_to_tick(35.00)  # 3500
    assert on_grid(tick, book["tick_size"])
    order = client.place_order(
        client_order_id="42",
        market_id=m["market_id"],
        side="buy",
        outcome="yes",
        type="limit",
        tick=tick,
        qty=10,
        tif="gtc",
        post_only=True,
    )