Investors made the Health Care Select Sector SPDR Fund (NYSEArca: XLV) the most popular U.S. ETF in the past week, pouring $346.4 million into a fund that for now seems to be a lightning rod for how the U.S. Supreme Court’s decision let stand the cornerstone of Obamacare plays out in financial markets.

The creations amounted to almost 8 percent of XLV’s assets, which totaled $4.75 billion as of Thursday, June 28—the end point of our five-day “weekly” survey. Overall, net outflows were about $1 billion and total U.S.-listed ETF assets fell to about $1.154 trillion from $1.158 trillion seven days earlier, according to data compiled by IndexUniverse.

The Dow Jones industrial average rose less than 30 points on the week to close at 12,602.26, though the Nasdaq dipped about a third of a percent to end the five-day period at 2,849.49.

Stocks have been volatile all week on continuing anxiety surrounding the eurozone, which dampened the effects of the High Court’s historic decision to preserve much of President Obama’s landmark 2010 health care bill, the implications of which still aren’t totally clear. XLV’s price ended on June 28 down 0.5 percent—a bit more in the red than the Dow, which ended 0.2 percent lower.

It’s worth noting that our weekly flows survey didn’t capture the effects of the Dow’s 278-point, 2.2 percent rally on Friday, June 29 that was related to optimism that European policymakers are making progress at a two-day summit in finding new ways to bring the continent’s debt crisis under control.

BOND And Other Bond ETFs

Among other noteworthy creations was the more than $200 million that Bill Gross’ Pimco Total Return ETF (NYSEArca: BOND) hauled in last week, a reflection both of investors’ nervousness about the macro situation and of BOND’s obvious allure.

Those inflows into BOND amounted to more than 13 percent of the fund’s assets, and demonstrate that it won’t be before long the $1.72 billion fund will cross the $2 billion barrier.

A few other bond funds that pulled in assets in the past week are the iShares iBoxx $ Investment Grade Corporate Bond Fund (NYSEArca: LQD) and the iShares iBoxx $ High Yield Corporate Bond Fund (NYSEArca: HYG), which gathered $233.8 million and $116.4 million, respectively.

Redemptions

The top three funds in terms of outflows were funds that canvass broad sectors of the U.S. equities universe, which, in the aggregate, suffered outflows of $2.37 billion in the five-day period.

Those funds and their redemptions are as follows:

• SPDR S&P 500 ETF (NYSEArca: SPY), $1.83 billion
• PowerShares QQQ Trust (NasdaqGM: QQQ), $473.0 million
• SPDR Dow Jones Industrial Average Trust (NYSEArca: DIA), $302.8 million

Also worth mentioning was the $283.1 million that flowed out of the PowerShares S&P 500 Low Volatility Portfolio (NYSEArca: SPLV).

The fund, which was launched in May 2011, has been hovering around the $2 billion AUM level for a few weeks. It ended the period with assets of $1.96 billion.

Its redemptions amounted to 12.6 percent of its assets.

Top 10 Creations (All ETFs)

Top 10 Redemptions (All ETFs)

ETF Weekly Daily Flows By Asset Class

Top 10 Volume Surprises, Funds >$50 mm AUM

Top 10 Weekly Performers, Excluding Leverage/Inverse Funds and <1,000 Shares Traded

Top 10 YTD Performers

Bottom 10 YTD Performers

Disclaimer: All data as of 6 a.m. Eastern time the date the article is published. Data is believed to be accurate; however, transient market data is often subject to subsequent revision and correction by the exchanges.