U.S stocks had another choppy session as corporate earnings drove the market once again. Apple was down big in Wednesday’s trading after its rare miss on Tuesday, while solid reports from Boeing and Caterpillar helped to boost the more industrial side of the economy.

Thanks to these mixed reports, stocks were relatively flat, as the S&P fell by half a point, the Nasdaq slumped by 0.3%, while the Dow jumped higher by about 0.5% thanks to some blue chip strength. In terms of sectors, tech was a modest loser along with health care plans, while some names in the oil and services space fell too. The only strength was in the broad health care, telecom, and big banks, which all led the charge higher in Wednesday’s session.

Still, the dollar was broadly weaker in Wednesday’s session as the euro and the Aussie dollar both strengthened against the greenback. Meanwhile, the 10 year was flat in the U.S. although investors did see some outflows in the German benchmark while the Spanish and Italian 10 years both saw their yields retreat a bit (read Three Great Tech ETFs that Avoid Apple).

In ETF trading, volume was surprisingly light despite it being the height of earnings season. Most of the big name equity products saw volumes lower than average while a number of the major emerging market funds also traded on light volume as well. However, investors did see some outsized movement in some of the commodity names, U.S. sector funds, and corners of the bond ETF market.

Particularly, investors saw an outsized level of interest in the iShares Dow Jones US Medical Devices ETF (IHI - ETF report) during Wednesday trading. The fund usually does about 59,000 shares in a normal day but saw a spike to just over 685,000 during today’s session (read Medical Device ETFs: A Better Way To Play Health Care?).

Earnings were primarily the driver of this boost in interest as a number of key device makers are slated to give their quarterly updates at some point this week. In fact, top five component Thermo Fisher Scientific (TMO - Analyst Report) reported before the bell today and surged roughly 8.7% in the session thanks to top and bottom line beats. This led to a resurgence of interest in the market segment and was a top reason for IHI’s relative popularity on the day.

Another fund that saw outsized interest was the iShares Dow Jones US Home Construction ETF (ITB - ETF report). The fund, which was a top performer year-to-date, saw nearly double the average volume thanks to a fresh new home sales number (see Five Best Performing ETFs (So Far) in 2012).

The report wasn’t exactly well-received by the market as the seasonally adjusted figure missed the 370k consensus by 20k. This pushed ITB down over 3.5% on the session and led the fund to a 5.5% loss over the past five day period.

(See more in the Zacks ETF Center)