What Would Happen If GPS Stopped Working Tomorrow? The Hidden Risks to Finance, Infrastructure and Technology

Author: Jade Reilly

Introduction

Most people think of GPS as the technology behind sat navs, delivery tracking and location-based apps. Useful, convenient and occasionally frustrating when it gets things wrong.

But that is only the visible layer.

The more important role of GPS is much less obvious. GPS provides positioning, navigation and timing services, and the timing part is where things become much more relevant to financial services, cybersecurity and infrastructure engineering.

GPS does not just help devices work out where they are. It helps systems agree on when something happened.

That distinction matters. If GPS stopped working tomorrow, the first thing many people would notice would be poor navigation. The bigger issue would be inside the systems where timing, sequencing and trust are critical. For trading infrastructure, cybersecurity and platform engineering teams, GPS is a useful reminder of a wider truth: some of the most important technology dependencies are the ones users never see!

Why GPS is really a timing system...

GPS is often described as a location system, but it also provides highly accurate time. GPS.gov explains that each GPS satellite contains atomic clocks, allowing receivers to synchronise to a precise timing signal without organisations needing to operate their own atomic-clock infrastructure.

That timing capability is why GPS appears in places most people would not expect: financial networks, telecommunications systems, power grids, transport infrastructure and data-driven business systems.

The important point is not that every system depends directly on GPS in a simple, single-threaded way. Most serious environments use layers of timing infrastructure, including GPS-disciplined clocks, timing appliances, network time protocols, grandmaster clocks, holdover capability and backup sources. But GPS is often part of the chain that helps those systems align to a common time reference.

For ordinary users, a few seconds rarely matter. For financial markets, telecoms and critical infrastructure, a few milliseconds - and sometimes far less - can matter a great deal.

"The most important thing GPS gives financial systems is not location. It is a shared sense of time."

What does GPS actually do in financial services?

In finance, timing is tied to trust.

Banks, exchanges, trading venues, payment providers and market participants all need reliable timestamps. Timestamps help establish when transactions happened, support audit trails, assist with regulatory reporting and allow firms to reconstruct events after an incident or market anomaly.

For trading infrastructure teams, this becomes even more important. Order events, market data feeds, execution reports, risk checks, venue connectivity and logs all need to make sense when viewed together. If the timing layer becomes unreliable, the technology may still appear to be running, but the evidence layer starts to weaken.

That is where GPS becomes relevant. GPS.gov states that major financial institutions use GPS to obtain precise time for internal clocks used to create financial transaction timestamps. NIST also identifies GPS timing dependencies across financial, telecommunications and electric power sectors.

This is not just a technical detail. If timestamps drift, disagree or become difficult to trust, it becomes harder to prove what happened, when it happened and in what order...

Would trading stop if GPS failed?

Probably not immediately, at least not at mature institutions with proper resilience planning.

Most serious financial organisations do not rely on a single timing source with no fallback. They may have backup clocks, alternative time feeds, holdover capability, monitoring and operational procedures for degraded timing conditions. But “not stopping immediately” is not the same as “no impact”.

A prolonged GPS outage, degraded GNSS signal or spoofed time source could create problems around timestamp confidence, event ordering, monitoring, regulatory reconstruction and incident response. In low-latency environments, even small timing inconsistencies can make troubleshooting harder because the logs no longer tell a clean story.

Imagine a market data plant where packets are still flowing, dashboards are mostly green and systems appear operational, but the timestamp source has started to drift. The issue may not be obvious at first. Then a trading incident occurs, and the team has to reconstruct what happened across order gateways, feed handlers, risk systems and venue connections.

If the clocks cannot be trusted, the investigation becomes harder before anyone even gets to the root cause. For trading infrastructure engineers, this is why timing is not a background detail ~ it is part of production integrity.

Why should market data and low-latency engineers care?

Market data engineering is not just about receiving packets quickly. It is about knowing whether data is complete, timely, ordered and explainable.

As touched on previously, GPS timing can support the timestamping and synchronisation required to understand what happened across distributed systems. That matters for latency measurement, packet capture, replay, post-trade analysis, incident response and performance tuning.

A timing problem may not look like a traditional outage. The system might not go down. Instead, the quality of the data degrades. Events become harder to sequence. Measurements become less reliable. Root-cause analysis becomes slower. That is often the more dangerous failure mode because teams can keep operating while confidence quietly erodes.

The practical question for infrastructure teams is not simply, “Do we use GPS?” It is: where does time enter the system, how is it distributed, how is it monitored, and what happens when that source becomes unavailable or untrusted?

Is GPS disruption a cybersecurity issue?

Yes, in the right context.

GPS and wider GNSS disruption can involve jamming, spoofing, equipment failure, local interference or environmental factors. EUSPA has identified spoofing and jamming threats as a priority to address at both system and user level, while NOAA notes that adverse space weather can affect GPS by disturbing the ionosphere and altering signal characteristics.

For cybersecurity teams, this makes GPS relevant to more than physical navigation. It becomes part of a broader resilience and trust problem.

If an organisation depends on GPS-derived timing, then interference with that signal can affect the systems that rely on it. That could include logging, event correlation, infrastructure monitoring, transaction records and incident reconstruction. In security operations, time matters because investigations often depend on correlating activity across systems accurately.

This does not mean GPS spoofing is the most likely cyber risk for every firm. It does mean security teams should understand whether positioning, navigation or timing dependencies exist inside the organisation, and whether those dependencies are monitored with the same seriousness as other critical infrastructure dependencies.

A useful way to frame it is this: jamming asks, “Can the system still operate without the signal?” Spoofing asks, “Would the system know if the signal was lying?”

Could GPS actually fail?

A complete global GPS failure is unlikely. That is not really the scenario most organisations should be planning around... the more realistic concern is disruption, degradation or loss of trust in GPS/GNSS signals in a region, facility, sector or operational context. 

This is why governments and infrastructure bodies increasingly talk about PNT resilience rather than GPS alone. The UK Government’s Positioning, Navigation and Timing overview describes PNT as vital to Critical National Infrastructure and the wider economy, while the National PNT Office exists to help improve PNT resilience across CNI and the wider economy.

For engineering teams, the better question is not, “What if GPS disappears tomorrow?” It is: what happens if the timing source we depend on becomes unavailable, degraded or wrong? This question leads to better design.

What would good GPS resilience look like?

Good resilience starts with dependency mapping. Teams need to know where GPS or GNSS-derived timing enters the organisation, which systems rely on it, and what the operational impact would be if that timing source degraded.

From there, the questions become more specific. What is the source of truth for UTC? How long can critical systems maintain accurate time if GPS is lost? Are timing sources monitored for drift? Are alerts routed to the right teams? Can systems compare multiple sources? Is there a documented runbook for degraded timing? Could the business prove timestamp accuracy during a regulatory or incident review?

These questions are not glamorous, but they are the difference between assuming resilience and engineering it.

For trading infrastructure teams, that may involve timing architecture, clock synchronisation, monitoring, failover paths and post-incident reconstruction. For cybersecurity teams, it may involve treating timing integrity as part of detection, response and forensic confidence. For platform teams, it may involve making time dependencies visible rather than leaving them buried in infrastructure assumptions.

"The systems that fail most dangerously are often the ones that looked boring enough to ignore."

Why this matters for engineers and technology hiring...

GPS is useful because it shows how easily a critical dependency can disappear into the background. When everything works, nobody thinks about the timing layer. When something fails, it suddenly becomes central to performance, trust, investigation and recovery.

That is a familiar pattern across modern infrastructure. The most important systems are not always the most visible ones. They are often the services, protocols, controls and dependencies sitting underneath the product experience, quietly deciding whether the wider environment is reliable or fragile.

For engineers, that changes the level of thinking required. It is not enough to understand a tool in isolation. The stronger question is how that tool behaves inside a larger system: what it depends on, what depends on it, how failure would show up, who would notice first, and how quickly the impact could be contained.

That is also why resilience has become such a valuable hiring signal across financial services, trading infrastructure, cybersecurity and platform engineering. The strongest candidates are rarely defined by one language, vendor or framework alone. They tend to understand production environments as living systems, shaped by dependencies, failure modes, observability, operational discipline, incident response and business risk.

GPS resilience is just one example, but the mindset applies far more broadly. The engineers who stand out are the ones who can build systems that work, while also asking the harder question: what happens when the thing we quietly rely on stops behaving as expected?

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SOURCES:

GPS.gov – GPS and Telling Time

GPS.gov – GPS and Financial Institutions

GPS.gov – GPS and Business Efficiency

UK Government – Positioning, Navigation and Timing Overview

UK Government – National Positioning, Navigation and Timing Office

NIST – An Evaluation of Dependencies of Critical Infrastructure Timing Systems on GPS

EUSPA – GNSS and Secure SATCOM User Technology Report

FAA – Satellite Navigation: Global Positioning System

NOAA Space Weather Prediction Center – Space Weather and GPS Systems