SINGAPORE (Reuters) -U.S. stock futures jumped and the dollar gained against safe-haven peers including the yen and Swiss franc on Thursday, after a U.S. federal court blocked President Donald Trump's "Liberation Day" tariffs from going into effect.

The Trump administration has appealed the ruling.

S&P 500 E-mini futures climbed 1.5% and the U.S. currency jumped 0.7% to 145.83 yen and 0.8% to 0.8339 Swiss franc.

Here are some quotes from market analysts:

KYLE RODDA, SENIOR FINANCIAL MARKET ANALYST, CAPITAL.COM, MELBOURNE

"It's massive news. It's long been suggested that the emergency powers Trump has used to implement tariffs were unconstitutional and that the power to enact tariffs sits with Congress.

"It sets up a battle that will likely end up the Supreme Court now. It's a situation fraught with danger because the administration may ignore the court's ruling, potentially placing greater strain on U.S. institutions at a time of increased stress.

"However, should the markets get their way, the courts could delay and then deny these tariffs, removing one massive risk and undoubtedly stoking risk appetite."

SHOKI OMORI, CHIEF DESK STRATEGIST, MIZUHO SECURITIES, TOKYO

"Initial reaction will be risk-on for risk assets such as equities. It's likely that we will see people buying USD as a funding currency expecting that global trade will re-ramp up."

"Given that trade talks have gone this far, (the United States) won't let countries go back to the pre-Trump era."

However, "it is good news that courts started to fight back against executive orders under rule of law."

FRANCES CHEUNG, HEAD OF FX AND RATES STRATEGY, OCBC, SINGAPORE

"The ruling gives an interim boost to risk sentiment which saw equity futures, bond yields and the dollar higher. For bonds and FX, the timing is convenient for an extension of the most recent trading momentum, where the dollar has already shown signs of rebounding and long-end bond yields have been facing upward pressure.

"That said, development on tariff and trade relations remains fluid. Investors may be reluctant to load heavy positions on either side of the trade."

FRANCIS TAN, CHIEF ASIA STRATEGIST, INDOSUEZ WEALTH MANAGEMENT

"Markets are simply reacting to all sorts of news for and against future growth, so investors ought to just be prepared for such news flows and look longer term rather than short-term trading on news. The U.S. dollar itself is quite undervalued because of concerns about U.S. deficits and debt. That should continue for a while until we get more clarity on fiscal issues."

YUNOSUKE IKEDA, HEAD OF MACRO RESEARCH, NOMURA, TOKYO

"At this point it's almost impossible to know if the tariffs will be completely unwound by this. But in the hypothetical situation that they are, it's natural to see dollar appreciation. Basically Trump's tariffs will lead to stagflation pressure on the U.S. economy, so reversing those tariffs would be a positive for the dollar."

CHARU CHANANA, CHIEF INVESTMENT STRATEGIST, SAXO, SINGAPORE

"The ruling removes an immediate overhang, even if it is not the final word on tariffs. Trump may still have scope to appeal or impose narrower, sector-specific tariffs, so policy uncertainty lingers.

"Markets had already moved past the initial Liberation Day tariff shock and expected negotiations. While the court ruling is a marginal positive for sentiment and helps to clear out the most bearish growth outlook bets, it does not remove uncertainty. Businesses still don't have clarity, and the policy path remains fluid.

"We could see the market unwinding some of the tariff-related moves, such as the weaker USD and Gold, EUR, JPY and EM FX could pull back. Short-end yields may rise as recession fears ease."

MATT SIMPSON, SENIOR MARKET ANALYST, CITY INDEX, BRISBANE

"It seems inevitable the Supreme Court will be ordered to weigh in on this one, which makes today's news more of a speedbump than a full-drawn conclusion. But for now, investors get a breather from the economic uncertainty they love to loathe."

HIROFUMI SUZUKI, CHIEF FX STRATEGIST, SMBC, TOKYO

"It's certainly a blow to the Trump administration. However, it's likely that the administration will proceed with appeals and other procedures in federal court. So, this block doesn't mean that policies regarding tariffs will completely stop.

"On the other hand, this is a domestic matter for the U.S., and I think that tariff negotiations will continue.

"In the financial markets, there's an initial reaction of a stronger dollar and weaker yen. However, considering judicial processes like appeals, I don't expect a continuous rise in the dollar."

SEAN CALLOW, SENIOR ANALYST AT ITC MARKETS, SYDNEY

"The kneejerk response of markets to the CIT ruling is intriguing - rather than taking it as simple risk-on news that should benefit the likes of AUD and NZD, the U.S. dollar is the main beneficiary.

"It appears as though while there must be significant caution over the ruling being overturned by higher courts, for now the weight of money is being placed on the possibility that U.S. courts prevent the White House from self-imposed economic damage, brightening U.S. growth prospects and the USD."

RAY ATTRILL, HEAD OF FX STRATEGY, NAB, SYDNEY

"We're just trying to work out what it might mean, but obviously the market is doing a kneejerk reaction so I guess it's reversing a lot of the moves that we've seen... you know all the direction of change has been opposite to what we have seen since Liberation Day, but it's not at all clear what this means.

"The assumption is that the tariffs that have been announced and are in place will stay in place... Our assumption is President Trump will appeal this trade court's decision and he has the right to appeal... And then it will be up to the federal court and what happens there? I have no idea. So this may be an absolute storm in a teacup or potentially something more significant.

"I think it's way premature basically to say that this has the potential to reverse a lot of the moves that we've seen in the last couple of months."

(Reporting by Kevin Buckland, Rocky Swift in Tokyo, Rae Wee, Ankur Banerjee and Johann M Cherian in Singapore, Stella Qiu in Sydney; Editing by Lincoln Feast.)