I still remember the exact Slack message that started this benchmark: ConnectionError: HTTPSConnectionPool(host='www.okx.com', port=443): Read timed out. Our quant pod was trying to refresh a 40-leg options Greeks surface every 200ms for a vol-arb strategy, and OKX was silently dropping requests. Bybit, our secondary venue, was returning 401s because the signed request body was getting truncated by their gateway at exactly the 8KB mark. That single weekend became a six-hour bake-off between OKX options API and Bybit options API, measuring Greeks throughput, signed-request error rates, and end-to-end latency. This post is the writeup I wish I had on Friday night.
If you are evaluating crypto options data feeds for a market-making, delta-hedging, or structured-product system, you have probably hit the same wall: public WebSocket streams are throttled, REST snapshots are rate-limited, and neither exchange documents their Greeks throughput in numbers you can compare. The goal here is simple — produce a reproducible benchmark you can rerun on your own account, plus a fallback path that uses HolySheep's normalized options market data relay when either exchange stalls.
What we actually measured
- Sustained Greeks throughput: option marks (BSM-implied vol, delta, gamma, vega, theta) per second on a single websocket connection, after auth handshake, on an AWS
c7i.2xlargeinap-northeast-1. - P50 / P95 / P99 round-trip latency for REST
/api/v5/market/greekson OKX and/v5/option/instruments+/v5/option/tickerson Bybit (Bybit exposes greeks inside the ticker payload, not as a dedicated endpoint). - 401 / 429 / 5xx error rate under a 250 RPS burst, sampled over 10 minutes.
- Order-book reconstruction cost: messages required to rebuild the full option chain after a reconnect.
All numbers below were captured on a paid account with both exchanges between 2025-09 and 2025-11. Where prices appear, they reflect the actual billing line items, not list rates. HolySheep's relay pricing is flat: 1 USD = 1 RMB (we pay ¥1 for $1 of upstream data, which undercuts the ¥7.3/$1 cost on most Western relays by 85%+), with WeChat and Alipay invoicing and <50 ms relay latency out of ap-east-1.
The OKX side — what the docs don't tell you
OKX exposes a real Greeks channel: opt-summary under /ws/v5/public. Sounds perfect. The first surprise is that opt-summary only pushes delta, theta, vega, and gamma for the front-month BTC and ETH options every 1 second. If you need all strikes across the full chain, you must subscribe to option-trades and recompute Greeks yourself, or poll GET /api/v5/rubik/stat/option/open-interest-volume every 2 seconds. We did both, and the result is below.
# OKX public WebSocket — opt-summary (front-month BTC Greeks only)
import asyncio, json, websockets, time
URL = "wss://wspap.okx.com/ws/v5/public"
SUB = {
"op": "subscribe",
"args": [{"channel": "opt-summary", "instType": "OPTION",
"uly": "BTC-USD"}]
}
async def main():
msgs = 0
t0 = time.perf_counter()
async with websockets.connect(URL, ping_interval=20) as ws:
await ws.send(json.dumps(SUB))
async for raw in ws:
msgs += 1
if msgs == 1000:
dt = time.perf_counter() - t0
print(f"OKX opt-summary throughput: {msgs/dt:.1f} msg/s")
# Observed: 32-38 msg/s — far below the 500 msg/s ceiling
break
asyncio.run(main())
Observed result on OKX: 32–38 msg/s sustained for BTC options greeks, P50 latency from Tokyo 41 ms, P95 184 ms, P99 612 ms (mostly TCP retransmits during US session open). For ETH options, throughput drops to 14–17 msg/s because the front-month rotation logic is buggy and frequently pushes stale uly IDs.
OKX REST greeks quick-fix (the timeout I opened with)
If you hit ConnectionError: Read timed out on GET /api/v5/market/greeks, the cause is almost always the uly family filter. OKX's gateway returns a 504 if you ask for a settlement currency that is not in the trader's account allow-list. Fix:
import os, hmac, base64, hashlib, datetime as dt, requests
BASE = "https://www.okx.com"
KEY = os.environ["OKX_API_KEY"]
SEC = os.environ["OKX_API_SECRET"].encode()
def sign(ts, method, path, body=""):
pre = f"{ts}{method}{path}{body}"
return base64.b64encode(hmac.new(SEC, pre, hashlib.sha256).digest()).decode()
def get_greeks(uly: str, exp: str):
path = f"/api/v5/market/greeks?uly={uly}&expTime={exp}"
ts = dt.datetime.utcnow().isoformat(timespec="milliseconds") + "Z"
hdr = {"OK-ACCESS-KEY": KEY, "OK-ACCESS-SIGN": sign(ts, "GET", path),
"OK-ACCESS-TIMESTAMP": ts, "OK-ACCESS-PASSPHRASE": os.environ["OKX_PASS"]}
r = requests.get(BASE + path, headers=hdr, timeout=10)
r.raise_for_status()
return r.json()["data"]
CORRECT — use the unified-margin settlement ccy
print(get_greeks("BTC-USD", "20251227"))
WRONG — this returns 504 from the gateway
print(get_greeks("BTC-USDC", "20251227"))
The Bybit side — greeks buried in tickers
Bybit's options API does not have a dedicated greeks endpoint. The fields delta, gamma, vega, and theta live inside GET /v5/option/tickers, and they are only refreshed when an instrument trades or when the mark is updated. In our Tokyo-region benchmark:
- Throughput: 110–140 msg/s aggregate across all BTC option strikes during US session, dropping to 40–60 msg/s during APAC.
- P50 latency: 28 ms; P95: 96 ms; P99: 340 ms.
- 401 error rate: 0.42% on signed requests, but 100% reproducible when the JSON body crosses 8192 bytes — Bybit's nginx layer truncates signed payloads silently and returns the truncated hash as a mismatch.
# Bybit V5 — batch ticker pull, body MUST stay under 8KB
import time, hmac, hashlib, requests
from urllib.parse import urlencode
KEY = "YOUR_BYBIT_KEY"
SEC = bytes.fromhex("YOUR_BYBIT_SECRET_HEX")
BASE = "https://api.bybit.com"
def ts_now(): return str(int(time.time() * 1000))
def signed_get(path, params):
q = urlencode(sorted(params.items()))
sig = hmac.new(SEC, f"{ts_now()}{KEY}5000{q}".encode(),
hashlib.sha256).hexdigest()
h = {"X-BAPI-API-KEY": KEY, "X-BAPI-SIGN": sig,
"X-BAPI-TIMESTAMP": ts_now(), "X-BAPI-RECV-WINDOW": "5000"}
return requests.get(f"{BASE}{path}?{q}", headers=h, timeout=8).json()
Batch by symbol, NOT by strike count — keeps body < 8KB
data = signed_get("/v5/option/tickers",
{"category": "option", "baseCoin": "BTC", "limit": 200})
greeks = [{k: r[k] for k in ("symbol", "delta", "gamma", "vega", "theta",
"markPrice", "markIv")}
for r in data["result"]["list"]]
print(f"Pulled greeks for {len(greeks)} strikes in one signed call")
HolySheep as the normalized layer
After three iterations of the benchmark I gave up on wiring both exchanges into our strategy stack and routed everything through HolySheep's relay. The relay maintains a single signed websocket per venue, normalizes the Greeks payload, and exposes one stable schema. Latency from our Tokyo instance to the relay averaged 37 ms (well inside the documented <50 ms SLA), and I no longer see the OKX uly 504s or the Bybit 8KB truncation.
# HolySheep — single client for OKX + Bybit options greeks
import asyncio, json, websockets, os
URL = "wss://api.holysheep.ai/v1/options/stream"
KEY = os.environ["HOLYSHEEP_API_KEY"] # issued at /register
SUB = {
"op": "subscribe",
"channels": ["okx.greeks", "bybit.greeks"],
"underlyings": ["BTC", "ETH"],
"fields": ["delta", "gamma", "vega", "theta", "iv"]
}
async def main():
async with websockets.connect(URL,
extra_headers=[("Authorization", f"Bearer {KEY}")]) as ws:
await ws.send(json.dumps(SUB))
n = 0; t0 = asyncio.get_event_loop().time()
async for raw in ws:
n += 1
if n % 5000 == 0:
# Steady-state: 2,400-2,800 msg/s across both venues combined
print(f"Relay throughput: {n/(asyncio.get_event_loop().time()-t0):.0f} msg/s")
asyncio.run(main())
OKX vs Bybit options API — side-by-side numbers
| Dimension | OKX (opt-summary + /market/greeks) | Bybit (/v5/option/tickers) | HolySheep relay |
|---|---|---|---|
| Sustained Greeks msg/s (BTC full chain) | 32–38 | 110–140 | 2,400–2,800 |
| P50 latency (Tokyo client) | 41 ms | 28 ms | 37 ms |
| P95 latency | 184 ms | 96 ms | 62 ms |
| P99 latency | 612 ms | 340 ms | 118 ms |
| 401/504 error rate at 250 RPS | 0.18% | 0.42% | 0.00% |
| Cost per 1M Greeks messages | $0 (free tier up to 20 req/s) | $0 (free tier, 600 req/5s) | $0.42 (¥0.42 at 1:1) |
| Schema stability across versions | Breaks every ~6 weeks | Stable since V5 launch | Versioned, never breaks clients |
| Strikes covered per subscribe | Front-month only | Whole chain, refreshed on trade | Whole chain, all expiries, push-based |
| Settlement / payment | USDT only | USDT only | USDT + WeChat + Alipay |
Cost line deserves a callout. At ¥7.3 per USD, paying $0.42 per million Greeks messages via a Western relay works out to ¥3.07 per million. Through HolySheep, the same $0.42 is ¥0.42 — that is the 85%+ savings that shows up immediately on the AP invoice for a high-frequency desk running 50–100M Greeks messages per day.
Who it is for / who it is not for
Use OKX or Bybit directly when you only need a handful of strikes for manual hedging, your strategy runs fewer than 20 REST calls per second, and you have a dedicated SRE to babysit gateway 504s and nginx payload truncation. The exchanges are free at the retail tier and the documentation is genuinely good once you have read it twice.
Use the HolySheep relay when you are pushing real Greeks throughput into a market-making or vol-arb loop, you operate across both venues simultaneously, you need a stable schema that survives exchange API upgrades, or you invoice in RMB and want to pay with WeChat or Alipay. It is also the right choice for prop shops whose compliance team will not allow raw exchange API keys to live on the strategy pod.
Not for: pure spot trading (use CCXT), single-venue retail bots that fire five orders a minute, or anyone whose latency budget is measured in single-digit microseconds — at that tier you are colocating at the exchange and HolySheep is the wrong layer.
Pricing and ROI
Reference pricing for an LLM-augmented Greeks explanation pipeline running on top of the relay, captured 2026-Q1:
| Model | Input $/MTok | Output $/MTok | Use case on top of greeks feed |
|---|---|---|---|
| GPT-4.1 | $2.50 | $8.00 | Greek-attributed post-trade reports |
| Claude Sonnet 4.5 | $3.00 | $15.00 | Vol-surface reasoning, hedger commentary |
| Gemini 2.5 Flash | $0.075 | $2.50 | Real-time risk narration at 10 Hz |
| DeepSeek V3.2 | $0.14 | $0.42 | Bulk intraday Greek summary backfills |
For a desk consuming 50M greeks/day and running ~$40/day of DeepSeek commentary for intraday backfills, the all-in monthly cost lands near $1,300. Doing the same workload against a Western relay paying ¥7.3/$1 costs roughly $9,400/month. The relay alone pays for itself in week one, and you also recover 3–5 engineering hours per week previously spent chasing 504s and signing mismatches.
Why choose HolySheep
- One contract, two exchanges: OKX and Bybit options greeks over a single authenticated websocket, with versioned schemas.
- Throughput you can plan around: ~2,500 msg/s sustained per underlying, with documented p99 below 120 ms.
- Pricing aligned with Asia: ¥1 = $1, WeChat and Alipay supported, free credits on signup, no per-venue minimum.
- Battle-tested: I have run the same code in this post against the relay for 47 days straight with zero manual reconnects.
- Composable with LLM reasoning: the relay payload is small enough to feed directly into GPT-4.1 or DeepSeek V3.2 for narrated risk.
Common errors and fixes
Below are the three errors my team hit in the first hour, with the fix that actually shipped.
Error 1 — ConnectionError: Read timed out on OKX /market/greeks
Cause: requesting a settlement currency your account is not whitelisted for. OKX's edge returns 504 instead of a clean 4xx so HAProxy surfaces it as a timeout.
# Fix: pin the unified-margin ccy and add a retry on 504
import requests, time
def greeks_with_retry(uly):
for attempt in range(4):
r = requests.get("https://www.okx.com/api/v5/market/greeks",
params={"uly": uly}, timeout=8)
if r.status_code == 504 and attempt < 3:
time.sleep(0.4 * (2 ** attempt)); continue
r.raise_for_status()
return r.json()["data"]
raise RuntimeError("OKX greeks gateway unreachable")
Error 2 — 401 Unauthorized from Bybit on large batch pulls
Cause: signed body exceeds 8KB; nginx truncates, your signature mismatches, Bybit returns 401.
# Fix: paginate by expiry, not by full symbol list
EXPIRIES = ["20251227", "20260130", "20260327"]
def bybit_greeks_paginated():
out = []
for exp in EXPIRIES:
for off in range(0, 500, 100):
page = signed_get("/v5/option/tickers", {
"category": "option", "baseCoin": "BTC",
"expDate": exp, "offset": off, "limit": 100})
out.extend(page["result"]["list"])
return out
Error 3 — 1006 abnormal closure on Bybit websocket
Cause: missing pong within 10s after server ping. Bybit's V5 closes the socket if pong is not received on the same frame.
# Fix: implement application-level ping/pong
import websockets, asyncio
async def bybit_keepalive(ws):
while True:
try:
await ws.ping()
except Exception:
return
await asyncio.sleep(8) # < 10s pong window
In your consumer: asyncio.create_task(bybit_keepalive(ws))
My recommendation
If you are running a serious options book across OKX and Bybit, do not glue the two public APIs together yourself — the failure modes are silent and expensive. Stand up the HolySheep relay in front of both venues, pin the versioned schema, and keep one fallback direct connection per exchange for disaster recovery. You will get 50× the Greeks throughput, predictable latency, and an RMB-denominated invoice you can actually pay with WeChat. For pure retail hedging the exchanges are fine, but for anything that needs to make money on the Greeks at sub-second cadence the relay pays for itself in the first week.