There hasn’t been this much media attention over a single decision since LeBron James took his talents to South Beach in 2010.

But in the annals of Wall Street, Federal Reserve Chairwoman Janet Yellen, and her colleagues on Thursday will make the most significant call in years, one that could prove pivotal for global financial markets.

Read: When is the Fed decision?

Wall Street analysts are deeply split over the Fed’s next move. Importantly, even if analysts knew how the Fed will proceed, the market’s response isn’t clear. The first rate increase in nearly a decade could spark turmoil in an array of assets from stocks to gold, but so could a delay, depending on how the central bank frames its decision.

The unpredictable nature of this meeting makes the conclusion of the Fed’s two-day meeting on Thursday distinctly different from any in history.

Read: Five things to listen for during Janet Yellen’s press conference.

Following are some of the assets and market trends to look out for after Thursday’s policy statement:

Volatility

The run-up to the meeting has been a bumpy ride for the stock market, with implied volatility on the S&P 500 SPX, +1.05% , as measured by the CBOE Volatility index VIX, -3.31% , itself often referred to as Wall Street’s fear gauge, trading around 21—slightly above its long-term average of 20 and at the top end of its range over the last four years.

If the Fed moves to increase its key lending rate by 25 basis points on Thursday, investors may interpret it as a sign of confidence in the economy and rally. Or they may also interpret it as the end of the cheap money era and selloff.

The Fed has the luxury of waiting until October or December or beyond to raise rates, but markets may interpret that as a lack of confidence in the economy. Or worse, the central bank could lose its credibility.

“By raising rates this week, the Fed can give markets some certainty and confidence, but any positive reaction will be short-lived,” said Bruce McCain, chief investment strategist at Key Private Bank. “Investors would immediately start thinking about the next move, which will be as uncertain as the initial one,” he added.

—Anora Mahmudova

Treasurys

The two-year Treasury yield spiked Wednesday to its highest point since April 2011. Tradeweb

A rate increase of any size could trigger a Treasury selloff, said James Kochan, chief fixed-income strategist at Wells Fargo Funds Management.

As investors repositioned for a potential rate increase, the yield on the two-year Treasury note TMUBMUSD02Y, 0.132% spiked higher on Tuesday to trade at its highest level since April 2011, while the yield on the one-year bill jumped to its highest level since April 2010. Short-term yields remain near those levels.

A rate increase “would likely be a shock” to short-term Treasurys, particularly the one-to-three year maturities, which are most sensitive to changes in the Fed-funds rate, said analysts at Bank of America, in a Tuesday note.

As for the benchmark 10-year Treasury yield TMUBMUSD10Y, 0.672% , it’s trading “squarely in the middle of the range seen over the last couple weeks,” Ian Lyngen, senior rates strategist at CRT Capital Group, said in a Monday note. The yield is also hovering around the middle of the range in which it traded over the past year, since September 2014.

The market was pricing in a 25% probability of a Fed rate increase, according to CME Group’s FedWatch tool.

HSBC’s fixed-income strategists earlier this week laid outhree different scenarios for the 10-year yield:

No tightening and continued data dependency: This scenario is the most dovish, but much of it is already priced in. The 10-year note yield should be in the 2.1% to 2.2% range.

No tightening and some signal pointing to a December move: The 10-year note yield should be in the 2.2% to 2.3% range.

A tightening and dovish signal to control the longer-term rate market: This would be a significant surprise for investors, so there is a significant likelihood that any dovish signal would be far outweighed by the surprise factor. The 10-year yield would move to 2.40% in this scenario.

—Ellie Ismailidou

Emerging-markets currencies

The dollar has strengthened by about 65% against the Brazilian real over the past year. And market strategists expect its rise to continue when the Federal Reserve raises interest rates. FactSet

Conventional wisdom in the currency market is that an interest-rate increase by the Fed will cause emerging-markets currencies to weaken as the prospect of higher returns on dollar-denominated assets lures investors back to the U.S., said Matt Weller, senior technical analyst at Forex.com.

This is what happened after then-Fed Chairman Ben Bernanke hinted at a coming reduction in the central bank’s program of asset purchases in May 2013. During the so-called “taper tantrum” that followed, emerging-markets currencies depreciated rapidly as sovereign bond yields rose. But Weller warned that things could be different this time around.

“Currencies with large current-account deficits, such as the Turkish lira USDTRY, +0.02% , Brazilian real USDBRL, , and South African rand USDZAR, +0.17% could be particularly vulnerable, as those economies are dependent on external capital for borrowing,” Weller said.

Meanwhile, the currencies of economies with large current-account surpluses like Thailand and Russia are less vulnerable to changes in Fed policy, Weller said. Most emerging-market currencies have been weakening this year. But they could find a reprieve if the Fed suggests Thursday that it will hold off on raising interest rates.

—Joseph Adinolfi

The euro/yen trade

The dollar’s appreciation against the euro stopped in March and has yet to resume. But many economists believe it will continue to appreciate once the Fed hikes rates. FactSet

The dominant theme in the foreign-exchange markets over the past year has been monetary-policy divergence. The idea that the Fed would be the first central bank among the developed economies to raise interest rates helped the dollar appreciate against the euro, yen and pound through the end of the first quarter.

Even if the Fed does hike rates on Thursday, a dovish message from policy makers could prevent the dollar from rising, currency strategists from Scotiabank said in a note to clients. But the strategists at most large investment banks, including Scotia, expect the dollar rally to resume toward the end of the year.

“While risk-off sentiment may support the [euro] EURUSD, -0.19% and [Japanese yen] USDJPY, +0.14% in the short run on a surprise hike, we continue to view the [dollar] as a strong bet broadly running into the year-end and into 2016 as central bank monetary policy settings diverge,” the Scotiabank strategists said.

Currency strategists at Bank of America Merrill Lynch and Goldman Sachs Group expect the dollar to rise to parity with the euro, its main rival, by year-end.

—Joseph Adinolfi

Gold

BullionVault, St. Louis Fed, LBMA

The above table from Adrian Ash, head of research at BullionVault, tracks gold’s US:GCZ5 percentage price-change over the three months before each previous rate-hike cycle begins, over the first three months after it starts, and over each cycle’s first 12 months, with average outcomes at the bottom, plus the average data for the entire period since 1970.

“If the central bank sends out a dovish signal on Thursday, this may help to boost stocks and undermine the dollar,” said Fawad Razaqzada, technical analyst at Forex.com, in a Monday note.

Under that scenario, “gold may benefit as lower rates for longer would decrease the relative opportunity cost for holding the metal,” he said. But the “likely ‘risk-on’ trade may mean that investors will pay less attention to gold and allocate more of their trading capital into equities.”

On the other hand, if the Fed decides to send out a more hawkish message, including a rate increase, “this may help unpin the dollar and undermine both stocks and buck-denominated gold,” said Razaqzada. So under both scenarios, “the upside appears to be limited for gold—unless of course we see massive drops in both equities and the dollar later in the week,” he said.

—Myra P. Saefong

Crude oil

Oil has been volatile, but might not move much after the Fed decision. Big Charts

U.S. oil prices may be destined to fall no matter what the Fed decides to do with interest rates.

Commodity traders have been fixated on the idea that if the Fed hikes rates, the U.S. dollar DXY, +0.16% will strengthen and in turn, pressure prices for dollar-denominated commodities such as oil CLV25, .

But Richard Hastings, macro strategist at Global Hunter Securities, believes that U.S. crude-oil prices will decline even further if the Fed doesn't hike rates.

“No hike means the Fed is reacting to weakness, and that would confirm a weaker demand profile for crude oil,” he said.

“If instead the Fed hikes, then it would be a hike into a mixed picture,” he said. “That, too, would equal more selling [in oil] because total infrastructure investments would get a bit more costly, thus reducing infrastructure outlays and crude-oil demand.”

Oil prices have already dropped by more than half from last summer’s peak, pressured by not just a global glut of crude supplies but concerns that demand from China, the world’s second-largest consumer, will weaken.

—Myra P. Saefong