BEIJING (TheStreet) -- The Chinese yuan fell off a cliff last week, losing a full year's worth of appreciation against the U.S. dollar after the People's Bank of China relaxed its managed float of the currency.

If this slippage becomes a trend, a weaker yuan could help Chinese exporters sell more stuff in the United States. It also could rekindle claims in Washington that Beijing "manipulates" its currency.

In China, immediate aftershocks resulted from the central bank's action. The yuan closed Friday at 6.22 to the dollar, down from 6.14 on Monday when the policy -- a widening of the band for daily yuan trading to 2% above or below the central bank's official rate -- took effect. The band had been 1%.

The last time 6.22 yuan returned a dollar's value was in March 2013. It then marched higher. By January 2014, it only took 6.04 yuan to buy $1. The rise in the yuan's value did not go unnoticed.

One shockwave after the central bank move hit Chinese airlines that used dollars to finance recent purchases of aircraft made by Boeing(BA) - Get Report and other suppliers, including China Southern (ZNH) - Get Report, China Eastern (CEA) - Get Report and Air China.

The Chinese government's Civil Aviation Administration said the yuan's depreciation since February had effectively raised liabilities for these airlines by a combined $700 million, according to the business newspaper Yicai Daily.

What had been steady appreciation for the yuan against the dollar between June 2010 and mid-February 2014 worked in the airlines' favor, the report said, boosting their exchange-rate gains by a combined $609 million in the first half of 2013.

Currency speculators profited from a reliable drumbeat of appreciation for nearly four years. The government doesn't these like so-called "hot money" investors who inject dollars into China, and for years they've tried stopping inflows by various means.

Speculators made a lot of money on the steady appreciation that started in mid-2010, after yuan-dollar exchange rates had barely moved between 2008 and 2010. The government then started signaling that the party was over in February by letting the yuan fall slowly against the dollar for several weeks. Then came the central bank action.

In fact, though, the central bank's move may have the opposite affect and encourage speculation in the long run, according to Hong Kong-based analyst Wei Yao of Societe Generale. She argued that the daily setting of a domestic-foreign currency parity rate by the central bank will become even more useful for speculators betting on the yuan's movement.

"In the recent episode of the yuan depreciation, the evidence is clear that it is also not entirely market-driven," Yao said. "This surprising tact may have tamed arbitrage flows for now... [but] if the market sees the policymakers' logic, central-bank-engineered volatility may just provide better entry points for speculation."

The impact of the yuan's depreciation was also felt by investors who use offshore yuan, mainly kept in Hong Kong banks, to bet on Chinese bonds and other yuan-denominated products on the mainland. They invest through a select group of asset managers licensed to participate in the Chinese government's Renminbi Qualified Institutional Investor (RQFII) program. ("Renminbi" is another name for yuan.)

A March 19 report in the Securities Times said investors were pulling their money out of RQFII funds managed by Hong Kong-based China Southern Asset Management (CSOP). The yuan's depreciation had prompted these exits from CSOP, the largest RQFII manager with $3.8 billion in assets under management.

On the other hand, some RQFII managers are reading the yuan's depreciation as a positive development. Rosita Lee, head of the Investment Products and Advisory Business at Hong Kong's Hang Seng Bank, said investors in her bank's yuan-denominated products are more aware than ever of currency risks. But they're looking at the long-term upside for the mainland bonds, stocks and other targets of RQFII funds.

"We do not see material change in the fund flow of these products" since the yuan's depreciation began, Lee said. "The increased (yuan) volatility will inevitably increase the risk faced by these investors, but RQFII products will continue to have their appeal.

"The widened trading band ... is perceived as a healthy move for the (yuan's) long-term development," she said.

At the time of publication, the author held no positions in any of the stocks mentioned.

This article represents the opinion of a contributor and not necessarily that of TheStreet or its editorial staff.