After abrupt interest rate rises in India, Turkey and South Africa, investors are now betting that Hungary and Russia will be the next emerging economies forced to defend their currencies, even though their finances look very different.
The three countries that acted last week - including Turkey which raised its rate by a dramatic 425 basis points - all rely heavily on foreign capital to power their economies.
Hungary and Russia, by contrast, run large current account surpluses. However, this has not stopped investors from selling off their currencies during the present rout, where they are lumping emerging markets together often regardless of major differences in the underlying economies.
Markets are pricing in a likelihood that Budapest and Moscow will also have to raise interest rates as the waves of emerging market selling - set off by concerns about Chinese economic growth and the U.S. Federal Reserve's decision to reduce a flood of cheap money - reach their shores.
The surprise actions by the central banks of India, Turkey and South Africa have eased some pressure on their markets. But this has shifted the focus to other countries where investors are worried about debt levels, inflation or just policymakers' credibility.
Investors have dramatically changed their expectations for Hungary and Russia. According to Societe Generale, interest rate markets are pricing a 167 basis point rate rise in Hungary over the next 12 months, contrasting with expectations of no change just two months ago.
In Russia, markets are pricing rates to rise 58 bps in the next 9 months, swinging from previous bets for a 33 bps cut, although many analysts believe the central bank will not act, at least for the moment.
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Nevertheless, both countries may need to act aggressively to get ahead of market expectations and boost real interest rates - rates adjusted for inflation - to lure foreign capital and restore investors' faith in their monetary policy.
"The focus is what the reaction function of central banks will be. If they are too slow and reluctant, you may see further weakness of currencies. Then we get into a negative spiral here," said Luis Costa, head of CEEMEA strategy at Citi.
Hungary was a prime example, he said. The forint hit a two-year low as concerns grew about the country's debt levels near 80 percent of annual economic output, its record of unconventional economic policies, and elections in April.
"If you want to stabilize your currency, the rationale is to deliver an interest rate shock. Hiking in line with market expectations doesn't work. You need what the Indonesians did."