Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

Good news isn't always good on Wall Street. That's certainly been the case today, as despite solid data out of America's manufacturing sector, the Dow Jones Industrial Average (^DJI 0.47%) has fallen around 30 points as of 2:15 p.m. EST, part of a wobbly day that has seen the blue-chip index bounce between rising and falling.

A strong report out of the Institute for Supply Management's Purchasing Manager's Index hasn't helped the Dow get any traction today, and most of the blue-chip index's 30 member stocks are in the red. 3M (MMM 0.67%) in particular has taken a big dive on the day so far. Let's catch up on what you need to know.

Manufacturing steams ahead
Manufacturing stocks have been hit hard in 2013, but the ISM's PMI report today for November showed good news. The PMI climbed for the sixth straight month, pulling up to a reading of 57.3 for November – a full 0.9 point above October's reading and far above the neutral 50 mark that indicates neither expansion nor contraction in the sector.

Employment and new orders both picked up for manufacturers, showing strength for both American workers and businesses alike. Exports and order backlogs continued to pick up their growth as well, although one piece of less-than-ideal data did slip into the PMI's report: Manufacturing prices saw their growth slip by 2.5 percentage points for the month, although they remained growing in November. Even with that, however, things are looking up for top manufacturers in the country that have had to deal with oversupply, tough competition, and weak demand in the wake of the recession.

Wall Street's having none of it, with the good data renewing the QE-infinity tapering fears that have sent the market wobbling in previous months. QE will end eventually, so it's best not to count on easing for your market moves.

3M, on the other hand, has taken a tough 3.6% hit so far today, sending the stock to the bottom of the Dow Jones. Morgan Stanley downgraded the stock to "Underweight" from "Equal-Weight", citing the company's poor growth recently. It's a fair point: While sales have picked up for 3M, operating income has fallen year over year through 2013's first nine months at all three of the company's largest business divisions by revenue. This stock surged this year by more than 38%, but if 3M can't rejuvenate its profit, shares might be in for a slight drawdown in coming months.

UnitedHealth's (UNH 0.40%) upsetting analysts today, too, although the stock's hardly moved for it. The company estimated that its full-year earnings for 2014 would come in at between $5.40 and $5.60 per share, missing average analyst projections that had seen a more optimistic look for the company's year ahead. UnitedHealth warned about the cuts to Medicare Advantage payouts under Obamacare, something that could hurt considering the company's growth in the area.

Nonetheless, UnitedHealth remains one of the best insurance stocks for your money: Its size and overseas growth give it some buffer against potential harm from the health care reform law's rollout, and the company's decision to participate in only a handful of state insurance exchanges under Obamacare should insulate it from considerable cost hikes. Today's news wasn't what investors wanted, but it's no terrible sign for UnitedHealth shareholders.