Markets can cope with bad news surprisingly well. What they struggle with is not knowing. When governments leave big questions open, such as what tax rates will be, how trade will work or which rules companies must follow, investors find it harder to value assets. That state of not knowing is called policy uncertainty, and it can weigh on shares, currencies and business investment long before any decision is made.
What policy uncertainty means
Policy uncertainty is the risk that government decisions on things like taxes, spending, trade, regulation or interest rates will change in ways that are hard to predict. It tends to rise around elections, budget fights, trade disputes and major legislation. It can also rise when governments send mixed signals or when the balance of political power shifts.
Why markets dislike it
Investors value a company by estimating its future profits and deciding how much to pay for them. If tax rates, tariffs or regulations could change sharply, those estimates become less reliable. To compensate for that risk, investors tend to pay less today. In other words, uncertainty raises the return investors demand, which lowers prices.
Companies feel it too. When the rules of the game are unclear, businesses often delay hiring and investment until they know more. That can slow the economy, which feeds back into profits and markets.
How it shows up in prices
Policy uncertainty often appears first in currencies and volatility measures. A country’s currency can weaken if investors fear unpredictable policy. Volatility indices, such as the VIX, which we look at in our guide to VIX term structure, tend to rise. Safe-haven assets like gold and, sometimes, government bonds may attract buyers. Sectors most exposed to the policy in question, for example technology during debates on regulation, can underperform the wider market.
How it is measured
Economists have built indices that track how often newspapers mention uncertainty alongside words about policy and the economy. These indices tend to spike during events such as elections, referendums and trade wars. Traders also watch prediction markets, options prices and surveys of business confidence for clues about how uncertain investors feel.
Uncertainty can fall as well as rise
The flip side is that markets often rally once uncertainty clears, even if the outcome is not the one investors hoped for. Knowing the rules, even tougher ones, lets people plan again. That is one reason US shares have historically tended to do well in the year after elections. It also explains why the first reaction to a political surprise, such as the 2026 US midterm result covered in our Morning Market Brief, can be followed by calmer trading once the picture settles.
The beginner’s takeaway
Policy uncertainty is the market’s discomfort with not knowing what governments will do. It tends to lower asset prices, lift volatility and delay business decisions. When it clears, markets often recover. Recognising when uncertainty is peaking can help you avoid selling at the worst moment. For a related idea, see our guide to why first market reactions often overshoot.
Managing uncertainty is at the heart of trading. If you want to see how well you handle it, take the free Samuel & Co Trading Trader Assessment.
