TOKYO/LONDON - The dollar hit three-month lows on Wednesday as the US' trade war with its partners escalated, while a major overhaul to German government borrowing triggered the biggest sell-off in the country's debt since the late 1990s.

In addition to the cocktail of tariffs and a seismic shift in German fiscal policy, investors also parsed through the start of China's annual sessions of its parliament, the National People's Congress (NPC), at which Beijing retained a goal of roughly 5 percent economic growth for 2025.

The euro hit its highest in four months, while European stocks surged. The biggest casualties were longer-dated German government bonds, caught up in their worst one-day selloff in more than 25 years as yields ripped higher.

Overnight, German political parties agreed to a 500 billion-euro ($534.75 billion) infrastructure fund and, crucially, an overhaul in borrowing limits that economists billed as "a really big bazooka".

"Last night Germany announced plans for one of the largest fiscal regime shifts in post-war history, perhaps with reunification 35 years ago being the only rival," Deutsche Bank strategist Jim Reid said.

"Everything you thought you knew about Germany's economic prospects three months ago, or even three weeks ago, should be ripped up and you should start your analysis from fresh," he said.

German 30-year yields - the rate the government pays to borrow over the very long term - rose by almost a quarter of a percentage point in early trading, which would have marked their largest rise since October 1998.

The 30-year bond was last up 15 basis points to yield 2.978 percent.

Longer-dated yields elsewhere rose too, with French 30-year rates up 11 basis points at 3.963 percent and even US Treasury bond yields up 3.5 bps at 4.55 percent.

Europe's STOXX 600 jumped by more than 1 percent to record highs. The prospect of a meaningful increase in European spending on security has sent the region's defence stocks soaring this month.

Trade war incoming

US tariffs on imports from Canada, Mexico and China went into effect on Tuesday, when President Donald Trump also delivered his State of the Union address, in which he touted his successes since taking office six weeks ago.

Canada and China retaliated immediately, while Mexican President Claudia Sheinbaum vowed to respond likewise, without giving details.

With a full-on trade war underway, crude oil hit six-month lows, while bitcoin found its feet around $87,800 following a volatile week.

"Fears about weaker US and global economic activity are manifesting in the markets, with cyclicals driving the sell-off," said Kyle Rodda, senior financial markets analyst at Capital.com.

Overnight, the US S&P 500 slid 1.2 percent, but futures rose 0.7 percent on Wednesday.

The US dollar index tumbled 0.4 percent to 105.11, bringing its losses over the last three days to 2.23 percent, the most in this timeframe since late 2022.

In the ascendant was the euro, which rose 0.5 percent to $1.0677, the most since mid-November, prompting a flurry of bullish forecasts from major investment banks.

Sterling rose 0.4 percent to $1.284, its highest since early December, while the Japanese yen strengthened, leaving the dollar down 0.25 percent at 149.44.

Oil fell for a third day on Wednesday, under pressure from concern over energy demand as tit-for-tat tariffs ramp up and from OPEC+ plans to raise output in April.

Brent futures fell 0.3 percent to $70.80 a barrel, having hit $69.75 the previous day, the lowest since September.