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).

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()
      }
      }
  • 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

  1. Use Crypto APIs (Binance/Coinbase) → $0.
  2. Polygon.io’s $49/month plan~$0.07/hour.
  3. Alpaca Paper Trading$0 (but delayed in production).
  4. Self-host a replay server (historical data) → $5/month VPS.

5. Rust Libraries to Process Feeds Efficiently

TaskRust CrateUse Case
WebSockettokio-tungsteniteBinance/Coinbase streams.
FIX Protocolquickfix-rsConnect to broker APIs.
DataFramespolarsClean/analyze tick data.
Zero-Copy Parsingnom or capnpDecode 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?