Tariff volatility rises

The latest tariff story is not really about one number. It is about a government that keeps changing the rules after businesses have already built budgets, signed contracts, and priced products. In the past week, the Trump administration raised pharmaceutical tariffs as high as 100 percent for some branded drugs, rewrote how steel, aluminum, and copper duties are calculated, and kept building a refund system for importers that paid tariffs the Supreme Court later wiped out. The result is a tariff regime that is harder to predict than it is to describe. That matters because companies can survive a high tariff they can see coming. They struggle with a tariff that keeps changing shape. On April 2, the White House said metal articles made mostly of steel, aluminum, or copper would still face a 50 percent Section 232 tariff, but the government would now assess that duty against the full value of many covered imports rather than a narrower metal-content measure. Derivative products made substantially of those metals would generally face 25 percent on full value. Some industrial and grid equipment got a temporary 15 percent rate through 2027. Products made abroad with entirely American metal got a lower 10 percent rate. Goods with 15 percent or less metal content were carved out. The headline rate barely moved. The bill facing importers often did. That same day, the administration rolled out its long-promised drug tariffs. Patented medicines and their active ingredients can face a 100 percent tariff, but only if the manufacturer has not cut a pricing deal with the government or committed to build in the United States. Companies that are negotiating with HHS and reshoring production can be exempt. Others can face a 20 percent tariff first, with the 100 percent rate arriving later. Large drugmakers have 120 days before the top rate takes effect. Smaller ones have 180. Some trading partners also got different treatment, including lower rates for countries with broader trade deals. So even here, the number on paper is not the number every importer will pay. That would already be hard to model. Then comes the refund mess. In February, the Supreme Court ruled that IEEPA does not authorize presidential tariffs, blowing up a large set of emergency duties imposed in 2025. Since then, Customs has been preparing to send money back. Yahoo Finance reported that more than 25,000 importers have requested refunds and that the government may repay more than $160 billion in invalid tariff costs. CBP has been pushing companies to set up ACH refund capability through its ACE system, which tells you how operational this has become: tariff policy is now a back-office cash-flow event. The deeper problem is that none of these moves sit still long enough to become normal. A steel buyer now has to ask not only what the tariff rate is, but what customs value the government will use, whether a product falls into a derivative category, whether its metal share crosses a threshold, and whether future guidance will change the answer again. A drug company has to price around a tariff schedule that depends on negotiations, plant construction, and deadlines that run into 2029. Forecasters trying to estimate inflation face the same trap. The tariff itself is only one variable. The enforcement formula, the exemptions, the retroactive refunds, and the next proclamation matter just as much. That is why tariff volatility is rising even when some published rates are unchanged. The government is no longer just taxing imports. It is continuously rewriting who pays, when they pay, how much of the invoice gets taxed, and whether the money might later come back. Customs posted new Section 232 guidance on April 3. Refund enrollment reminders went out days earlier. By then, the tariff had already become less like a tax table and more like a moving target.