On Saturday, August 22, a 50% US tariff on a list of Canadian goods took effect after trade talks broke down, and the impact of tariffs on markets showed up quickly in the Canadian dollar. The goods covered make up around 5% of Canada’s exports to the US, yet the Canadian dollar weakened about 0.6% by the next business day, with the Bank of Canada’s daily average rate for one US dollar at 1.3842 Canadian dollars on Monday, up from 1.3760 on the Friday. A narrow tariff can produce a broad market move because it touches costs, prices, currencies and central bank plans at the same time, and each of those reaches a different market.
Quick answer: The impact of tariffs on markets runs through several channels at once. They raise costs for importers, which can squeeze company margins or lift consumer prices, and they can weaken the currency of the country being targeted. Higher prices can feed into inflation and change what central banks do next. That’s how a tariff on one product list can move currencies, stock indices and commodities.
See Trade Headlines Reach the Currency Market
Trade disputes often show up first in the currencies of the countries involved, and every major pair carries the news of two economies.
How US Tariffs Changed During 2026
A Supreme Court ruling removed one set of tariffs this year, and the administration rebuilt them under other laws.
| Date | What happened |
|---|---|
| February 20 | The Supreme Court ruled 6 to 3 that the emergency powers law known as IEEPA doesn’t authorize tariffs |
| February 24 | A temporary 10% tariff on most imports took effect under Section 122, a law limited to 150 days |
| July 24 | Section 301 tariffs of 10% or 12.5% on goods from 60 trading partners replaced the temporary tariff |
| August 22 | 50% tariffs on listed Canadian goods took effect under Section 338 |
| September 8 | Canada’s dollar-for-dollar counter-tariffs on C$27.6 billion of US goods took effect |
| September 27 and 28 | The US and China agreed to pursue tariff cuts on $60 billion of goods and extended their truce to January 10 |
| October 30 | The US removed plywood and some paper products from the Canadian list and added valves and carpets |
Sources: EY on the Supreme Court ruling, Morgan Lewis on Section 122 and Section 301, Covington on the Canada tariffs, Reuters via the Honolulu Star-Advertiser and the White House.
Each row was a separate trade headline, and each one gave traders something new to price.
Who Pays Decides How Tariffs Impact Markets
A tariff is a tax on imports, paid to US Customs by the company bringing the goods in. What happens next decides which markets feel it.
- The importer absorbs it: margins shrink, which can weigh on that company’s shares
- The importer passes it on: shoppers and businesses pay more, which can show up in inflation data
- The foreign supplier cuts its price: the exporter’s margins shrink, and its home economy takes the hit
Worked Example: A 50% Tariff on One Shipment
Valves joined the list of Canadian goods facing the 50% US tariff on October 30. Take a US distributor that buys a Canadian valve for $100 and sells it for $160, keeping $60, a gross margin of 37.5%.
The tariff adds $50 to each valve, taking its cost to $150. The distributor now has three broad choices:
| Choice | Selling price | Margin per valve | Gross margin |
|---|---|---|---|
| Absorb the full tariff | $160 | $10 | 6.3% |
| Pass on the full tariff | $210 | $60 | 28.6% |
| Split it | $185 | $35 | 18.9% |
Figures are illustrative, based on the 50% Section 338 rate in Covington’s summary and the valves addition in the White House fact sheet.
Absorbing it protects sales but cuts the margin to $10, the kind of change analysts mark down in earnings estimates. Passing it on keeps the dollar margin but raises the customer’s price by 31%, and if enough businesses do the same, the effect can reach consumer prices. The Canadian maker loses either way if its US orders fall, and losses like that are what currency traders try to price when a tariff takes effect.
Where the Impact of Tariffs on Markets Shows Up
Currencies
Currencies are often where the impact of tariffs on markets appears first. The targeted country’s currency tends to weaken, because traders expect its exports and growth to slow. The table that follows shows the Canadian dollar around the key dates of the dispute. Our forex trading page explains how growth and rate expectations feed into a pair.
Stock Indices and Sectors
Tariffs hit some companies far harder than others. Importers and carmakers with cross-border supply chains tend to react first. Russell Investments notes that the US also plans to raise the tariff on Canadian cars to 50% from January 1, 2027, a headline that falls directly on auto stocks and the indices that hold them. The indices trading page covers how sector weights shape an index’s reaction.
Commodities
Trade deals can move farm prices as sharply as tariffs. When the US and China published their September lists, China left out non-seed soybeans, the biggest US farm export to China at $16.2 billion in 2025, and Chicago soybean futures plunged the following Monday, Reuters reported.
Bonds and Central Banks
The slowest part of the impact of tariffs on markets often runs through interest rates. Tariffs can lift prices in the country imposing them, and that can change the path of rates. Central banks then have to judge if the price rise is a one-off or the start of something broader. Our article on central bank decision days covers how markets price those choices.
Why Tariff Headlines Move Markets Before the Tariffs Start
Much of the impact of tariffs on markets comes before the tariffs start, because the news of a tariff usually arrives weeks ahead of the tariff itself.
| Date | Event | US dollar in Canadian dollars (daily average) |
|---|---|---|
| July 17 | Friday before the announcement | 1.4014 |
| July 21 | Day after the US announces 50% tariffs on Canadian goods | 1.4095 |
| August 21 | Talks break down | 1.3760 |
| August 24 | First business day after the tariffs take effect | 1.3842 |
| September 4 | Last business day before Canada’s tariffs start | 1.3840 |
| September 8 | Canada’s counter-tariffs take effect | 1.3784 |
Figures from the Bank of Canada’s daily exchange rates. A higher number means a weaker Canadian dollar.
The Canadian dollar weakened about 0.6% after each of the first two headlines. When Canada’s own tariffs began on September 8, two weeks after they were announced, it firmed slightly. Oil prices and interest rates move the Canadian dollar too, which is why traders treat a currency’s reaction on any single day as one piece of evidence.
How to Read the Next Trade Headline
Judging the impact of tariffs on markets from a new headline usually starts with these details.
- Scope: the value of goods covered and their share of a country’s exports
- Timing: the gap between announcement and effective date, and any pause or deadline
- Exemptions: goods qualifying under the USMCA, for example, are exempt from the Section 301 tariffs
- Retaliation: a matching response can widen the dispute to new sectors
- Deals and deadlines: the US and China truce now runs to January 10, 2027
Our fundamental analysis guide shows how traders weigh news like this against what’s already expected.
Key Takeaways
- The impact of tariffs on markets reaches well beyond the goods being taxed.
- Who absorbs a tariff decides where it shows up first, in company margins or in inflation data.
- The targeted country’s currency often weakens, as the Canadian dollar did after the US announced and then applied its 50% tariffs.
- Trade deals can move commodities as much as tariffs, as soybean futures showed in September.
- Much of a tariff’s expected effect can be priced in between the announcement and the effective date.
Frequently Asked Questions
How do tariffs affect the stock market?
Tariffs affect the stock market mainly through company earnings. Importers either absorb the extra cost, which shrinks their margins, or pass it on, which can cut sales. Sectors with cross-border supply chains, such as autos and retail, tend to react most. Indices can also fall if traders expect tariffs to slow growth or push interest rates higher.
Do tariffs make a currency stronger or weaker?
Tariffs often weaken the currency of the country being targeted, because its exports and growth are expected to suffer. The Canadian dollar weakened about 0.6% after the US applied 50% tariffs in August 2026. The currency of the country imposing tariffs can move either way, depending on what traders expect for its growth and interest rates.
Who pays for tariffs?
The importing company pays a tariff to its own country’s customs agency when goods arrive. The cost is then shared in some mix between that importer, its customers and the foreign supplier, depending on who has more pricing power. The split can shift over months as contracts are renegotiated and supply chains move.
Why do markets react to tariff threats?
Markets react to tariff threats because prices reflect what traders expect to happen. A threat raises the chance of a tariff, and prices adjust to that chance straight away. If the tariff is later delayed, narrowed or dropped, markets can reverse just as quickly, which is why trade news often causes sharp moves both ways.