Live market data feeds can be extremely expensive (e.g., Nasdaq TotalView costs $5,000+/month), but there are budget-friendly (even free) ways to get real-time or near-real-time data for learning and prototyping. Here’s how to do it without breaking the bank:
1. Free (or Cheap) Live Data Sources
A. Crypto Markets (Cheapest Real-Time Data)
- WebSocket APIs (Free):
- Binance:
wss://stream.binance.com:9443/ws/btcusdt@depth(order book updates). - Coinbase Pro:
wss://ws-feed.pro.coinbase.com(FIX-like protocol). - Rust Implementation:
#![allow(unused)] fn main() { use tokio_tungstenite::connect_async; use futures::StreamExt; async fn binance_order_book() { let url = "wss://stream.binance.com:9443/ws/btcusdt@depth"; let (ws_stream, _) = connect_async(url).await.unwrap(); ws_stream.for_each(|msg| async { println!("{:?}", msg); }).await; } } - Cost: $0 (rate-limited).
- Binance:
B. Stock Market (Delayed or Low-Cost)
- Polygon.io (Stocks/Crypto):
- Free tier: Delayed data.
- $49/month: Real-time US stocks (via WebSocket).
- Alpaca Markets (Free for paper trading):
- WebSocket API for stocks/ETFs (free with rate limits).
- Twelve Data ($8/month for real-time stocks).
C. Forex & Futures (Low-Cost Options)
- OANDA (Forex, free API with account).
- TD Ameritrade (Free with account, but delayed).
2. Simulated Data (For Backtesting)
- Generate Synthetic Order Books:
- Use Poisson processes to simulate order flow in Rust:
#![allow(unused)] fn main() { use rand::Rng; fn simulate_order_flow() -> Vec<(f64, f64)> { let mut rng = rand::thread_rng(); (0..100).map(|_| (rng.gen_range(150.0..151.0), rng.gen_range(1.0..10.0))).collect() } }
- Use Poisson processes to simulate order flow in Rust:
- Replay Historical Data:
- Download free NASDAQ ITCH files (historical) and parse them in Rust (itch-parser).
3. Ultra-Low-Cost Hardware Feeds
- SDR (Software-Defined Radio):
- Hack NYSE’s microwave towers (just kidding… or are you?).
- Real use: Capture ADS-B (airplane data) as a latency benchmark project.
- Raspberry Pi + FPGA:
- Build a nanosecond-precision timestamp logger (cheaper than commercial solutions).
4. How to Stay Under $10/Hour
- Use Crypto APIs (Binance/Coinbase) → $0.
- Polygon.io’s $49/month plan → ~$0.07/hour.
- Alpaca Paper Trading → $0 (but delayed in production).
- Self-host a replay server (historical data) → $5/month VPS.
5. Rust Libraries to Process Feeds Efficiently
| Task | Rust Crate | Use Case |
|---|---|---|
| WebSocket | tokio-tungstenite | Binance/Coinbase streams. |
| FIX Protocol | quickfix-rs | Connect to broker APIs. |
| DataFrames | polars | Clean/analyze tick data. |
| Zero-Copy Parsing | nom or capnp | Decode binary market data. |
6. Dirty Cheap HFT Data Pipeline (Example)
use tokio_tungstenite::connect_async; use tokio::sync::mpsc; // 1. WebSocket feed (Binance) async fn ws_feed(tx: mpsc::Sender<String>) { let (ws, _) = connect_async("wss://stream.binance.com/ws/btcusdt@depth").await.unwrap(); ws.for_each(|msg| async { tx.send(msg.unwrap().to_text().unwrap().to_string()).await.unwrap(); }).await; } // 2. Order book builder async fn order_book_builder(rx: mpsc::Receiver<String>) { while let Some(msg) = rx.recv().await { println!("Update: {}", msg); } } #[tokio::main] async fn main() { let (tx, rx) = mpsc::channel(1000); tokio::spawn(ws_feed(tx)); order_book_builder(rx).await; }
Cost: $0 (just your laptop and Wi-Fi).
Key Takeaways
- Start with crypto (Binance/Coinbase) → free and fast.
- For stocks, use Polygon/Alpaca → ~$50/month.
- Simulate data if you’re just learning HFT strategies.
- Optimize later—first prove your strategy works, then pay for premium data.
Want to dive into parsing Nasdaq ITCH or building a FIX engine next? Or optimize the above pipeline for microsecond latency?