众所周知，很多美国制药企业为了避税，采取了诸如收购、反收购的方式，将公司主体迁往诸如冰岛、新西兰等税收优惠的国家。很多药企对于收购他国企业，毫不避讳地表示就是为了合理避税，看起来是美国制药公司收购了小公司，财务上却走了小公司的帐，形成了实际上的反收购。对此引起了美国国会的不满。近期美国将进行制药行业税收整治，行业内认为该行动会整体影响美国制药相关股市。这个消息，引起了制药界人士的担心。

新闻原文如下：

Pharma shares sink as U.S. threatens tax-inversion crackdown

August 7, 2014 | By Carly Helfand

U.S. drugmakers have embraced the tax inversion strategy with open arms as of late, buying up foreign companies right and left and hauling overseas to take advantage of their lower rates. But U.S. officials are looking to stop them in their tracks--an intent that has some pharma investors worried.

Wednesday, the U.S. Treasury Department said it's reviewing a "range of options" to discourage tax inversions, which could include policies that "meaningfully reduce the tax benefits," of the deals, it said in a statement seen by Bloomberg.

The comments spooked investors, with American depository receipts for Dublin-based drugmaker Shire ($SHPG)--recently scooped up in an inversion by Illinois company AbbVie ($ABBV)--recording a 3.6% drop, their biggest single-day slip since last May, and those of former inversion target AstraZeneca ($AZN) declining 2.1%, the news service notes.

Shares of Swiss biotech Actelion ($ATLN) and Irish pharma Alkermes ($ALKS) were each down at least 2.5%, according to the Financial Times.

"We're seeing the inversion trade unwind," BMO Capital Markets analyst Alex Arfaei told Bloomberg. "Many inversion targets had run up as the pace of deals picked up recently."

As Arfaei pointed out, some of the recent trans-Atlantic deals--including AbbVie's--have more to them than just a tax inversion. The Abbott-spinoff's pickup, for instance, will help it diversify beyond Humira, the best-selling arthritis drugs that brings in the bulk of the company's sales.

But that won't stop the Treasury and lawmakers from going forth with their plans to curtail the transactions. As an aide to Ron Wyden, Democratic chair of the Senate finance committee, told the FT, "We're going to push forward to put laws in place to stop companies from abusing this loophole."