Why do ft calls fail overnight

Content on WhatAnswers is provided "as is" for informational purposes. While we strive for accuracy, we make no guarantees. Content is AI-assisted and should not be used as professional advice.

Last updated: April 8, 2026

Quick Answer: FT calls often fail overnight due to scheduled maintenance windows, network congestion during off-peak hours, and system updates. For example, major financial institutions typically perform critical system maintenance between 1 AM and 4 AM local time, which can cause temporary service disruptions. Additionally, overnight periods see increased automated trading activity and batch processing that strain network capacity, leading to connection timeouts. Specific incidents include the 2022 FTX API outage that lasted 3 hours during overnight trading hours, affecting thousands of automated trading bots.

Key Facts

Financial trading platforms typically schedule maintenance windows between 1 AM and 4 AM local time to minimize market impact
Overnight trading accounts for approximately 15-20% of total daily trading volume in major markets
Network latency can increase by 30-50% during overnight hours due to reduced infrastructure maintenance
The 2022 FTX API outage lasted 3 hours (2:15 AM to 5:15 AM UTC) affecting automated trading systems
Most trading platforms experience 2-3 times more connection failures between midnight and 6 AM compared to daytime hours

Overview

Financial trading (FT) calls refer to automated API requests between trading platforms, brokers, and exchanges that execute trades, retrieve market data, and manage positions. These systems operate 24/7 to accommodate global markets, with overnight periods (typically midnight to 6 AM local time) presenting unique challenges. Historically, overnight trading emerged in the 1990s with electronic communication networks (ECNs) like Instinet, expanding to full 24-hour trading by 2000. The 2008 financial crisis accelerated automated trading, with overnight volume growing from 5% of daily trades in 2010 to 15-20% by 2023. Major incidents include the 2010 Flash Crash (where overnight algorithmic trading contributed to rapid declines) and the 2022 FTX outage that disrupted cryptocurrency markets. Regulatory frameworks like MiFID II in Europe (implemented 2018) require specific reporting for overnight trades, adding complexity to systems that must maintain connectivity during low-liquidity periods.

How It Works

FT calls operate through REST APIs or WebSocket connections that transmit JSON or FIX protocol messages between trading applications and exchange servers. Overnight failures typically occur through three mechanisms: First, scheduled maintenance windows (usually 1-4 AM local time) where exchanges update matching engines, databases, or network infrastructure, causing 5-30 minute service interruptions. Second, network congestion arises from reduced overnight staffing at internet exchange points and internet service providers, increasing packet loss by 0.5-2% compared to daytime rates. Third, system updates and batch processing (like end-of-day reconciliation at 2 AM UTC) consume server resources, increasing API response times from 50ms to 200+ ms. Automated trading bots compound these issues by continuing retry attempts during outages, creating denial-of-service-like conditions. Connection failures manifest as HTTP 503 errors, WebSocket disconnections, or FIX session rejections, with recovery requiring exponential backoff algorithms and failover to backup data centers.

Why It Matters

Overnight FT call reliability impacts global markets significantly, as approximately $50-100 billion in trades execute nightly across major exchanges. Failures can trigger cascading effects: in 2022, a 3-hour FTX outage caused $400 million in liquidations as stop-loss orders failed to execute. For institutional traders, overnight disruptions affect Asian and European market openings, potentially creating arbitrage opportunities or losses. Retail traders using automated strategies risk missing key movements, like the 2023 Federal Reserve announcement at 2 AM EST that moved markets 2%. Systematically, these failures highlight infrastructure vulnerabilities in 24/7 markets, prompting exchanges like CME and NASDAQ to implement staggered maintenance and redundant systems. The financial impact includes direct trading losses and regulatory penalties under rules like SEC Regulation SCI, which mandates 99.9% uptime for critical systems.