????隨著美聯儲（Federal Reserve）退出債券購買計劃，它需要考慮的另一個風險是：越來越多的新興市場下跌是否會引發美國金融危機？

????由于美聯儲可能放緩債券購買節奏，引發美國利率上升，今夏新興市場備受煎熬。印度盧比兌美元匯率自5月以來已跌去20%。土耳其里拉也跌了15%。這兩個國家的股市也遭受了打擊。華爾街多年偏愛的巴西股市今年也已跌去了20%。

????目前，銀行投資者看起來還不太擔憂。由于新興市場狀況進一步惡化，銀行股價在過去一個月下跌了4%。但投資者總是不愿承認現實。“總體上，銀行投資者并不是普遍擔心，”跟蹤銀行股的瑞信（Credit Suisse）分析師莫什?奧倫巴表示。“如果突然之間，某個新興市場出現暴跌，人們才會措手不及地急于了解風險敞口。”

????6月初，摩根大通（JPMorgan Chase）倫敦辦公室的銀行業分析師們寫了一份名為《Fed節流：誰擔憂新興市場拋盤？我們！》（Fed Tapering: Who is Afraid of EM [emerging market] Selloff? We Are!）的報告。報告稱，利率上漲將顯著減緩新興市場的債券銷售和大銀行的業務。這份報告著重分析了歐洲銀行業，認為渣打（Standard Charter）和匯豐（HSBC）這兩家英國銀行的業務損失將最為嚴重。

????在美國，損失最嚴重的銀行可能會是花旗（Citigroup）。根據花旗最新的業績演示，該行有近半收益來自于新興市場。事實上，已有多家銀行宣布將撤出巴西市場，雖然數月前，包括高盛（Goldman Sachs）在內的很多華爾街公司還有著非常雄心勃勃的巴西擴張計劃。

????但真正可能引發金融危機或(由于金融危機擔憂而引發)市場動蕩的并不是銀行收入下降，而是如果這些市場繼續震蕩，銀行將損失多少。要搞清這些數字很困難。

????銀行的確會在財報中按國別披露可能會有多少的投資或貸款損失。但它們只披露自己持有大量頭寸或貸款業務國家的數據。而且，它們通常也不會把全球新興市場的所有風險敞口進行匯總處理。

????舉例來說，摩根士丹利（Morgan Stanley）在財報中表示，如果它在巴西的投資和貸款全都失敗，損失將達到46億美元，在中國損失30億美元。但這些數據是經過對沖和調整后的數據。請忽略這些數據（對沖并不總是那么靠譜，看看摩根大通的倫敦鯨事件就知道了）。根據美國聯邦金融機構檢查委員會（Federal Financial Institutions Examination Council, FFIEC）的數據，摩根士丹利在巴西的最糟糕情形可能損失170億美元。根據FFIEC的同一數據，這家銀行在韓國可能損失100億美元。韓國并不是摩根士丹利財報中重點列出的國家。將所有這些潛在損失加在一起，新興市場聽起來確實是摩根士丹利投資者應該關注的領域。在最糟糕情形下，單單上述三個市場的損失就可以讓這家銀行660億美元的資本金損失慘重。

????Here's yet another risk the Federal Reserve might want to consider as it exits its bond buying program: Could the growing rout in emerging markets create a financial crisis back home?

????Rising interest rates in the U.S., sparked by indications that the Fed may slow its bond buying, have translated into a summer of pain for emerging markets. India's rupee has plunged 20% against the dollar since May. And Turkey's lira is down 15%. Stock markets in both countries have taken hits as well. Brazil's stock market, too, long a darling of Wall Street, is down 20% this year.

????Right now, bank investors don't seem too concerned. Shares of bank stocks have fallen 4% in the past month as the situation in emerging markets has gotten worse. But investors often stay in denial long after they should. "In general, bank investors haven't been overall concerned," says Credit Suisse analyst Moshe Orenbuch, who follows bank stocks. "If all of a sudden one of these markets explodes then everyone will be rushing to look at exposures."

????In early June, bank analysts in JPMorgan Chase's London office wrote a report titled "Fed Tapering: Who is Afraid of EM [emerging market] Selloff? We Are!" The report said that rising interest rates would dramatically slow bond sales in emerging markets and work for the big banks. The report was focused on the European banks and said that British banks Standard Charter and HSBC stand to lose the most business.

????In the U.S., that bank could be Citigroup (C). According to the bank's most recent earningspresentations, Citi generated nearly half of all its earnings in the emerging markets. Already a number of banks say they're pulling back from Brazil, where a number of Wall Street firms, including Goldman Sachs (GS), had ambitions plans to expand just a few months ago.

????But what really drives financial crises, or shocks in the market on fears of them, is not lower revenue, but how much banks could lose if those markets continue to tumble. Figuring out that number can be tough.

????Banks do disclose in the notes to their financial statements how much money they could lose, either because of investment or loans, by country. They only disclose that figure for countries where they have significant holdings or lending operations. And they generally don't tally up all the exposures they have to emerging markets around the world.

????Morgan Stanley (MS), for instance, says in its financial statements it could lose as much as $4.6 billion if all its bets and loans in Brazil went bad, and another $3 billion in China. But those figures are after hedges and adjustment. Ignore those -- hedges don't always work like they should, just ask JPMorgan's London Whale -- and Morgan Stanley's worst case Brazil scenario looks more like $17 billion in losses, according to figures from the Federal Financial Institutions Examination Council. In South Korea, the bank could lose $10 billion, according to the same government stats. South Korea isn't one of the nations that Morgan Stanley highlights in its own financial statements. Add all those potential losses up, and emerging markets sound like something Morgan Stanley investors should be watching. Losses in those three markets alone, again in the worst case scenario, could put a significant dent in the bank's overall capital of $66 billion.