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.

It's Valentine's Day, so perhaps investors are distracted this Friday morning, as U.S. stocks are little changed, with the benchmark S&P 500 and the narrower Dow Jones Industrial Average (^DJI -0.76%) up 0.10% and 0.20%, respectively, at 10:15 a.m. EST. Nevertheless, today could turn out to be a test for shares of Twitter (TWTR), as its first post-IPO share "lockup" expires. Meanwhile, Jawbone has nearly completed a funding round that values the private wearable technology company at $3 billion. Richly valued, yes, but with Apple (AAPL 0.45%) CEO Tim Cook recently saying "we have no problem spending 10 figures for the right company," Jawbone is (or ought to be) a legitimate target.

 According to SEC filings, up to 9.87 million shares of Twitter become eligible for sale by nonexecutive employees today. Bloomberg reported that if all the shares were to be sold on the open market, the stock's float (shares available for trading) would rise by by 12% to 90 million, so it represents a sizable slug. (Note, however, that S&P Capital IQ lists the current float as 284 million.)

No insiders sold shares as part of Twitter's November initial public offering, so they have not been able to realize massive paper gains on their holdings; Twitter's stock has more than doubled from the $26 offering price. However, the expiration of the lockup appears to be having no adverse effect on the stock price this morning; in fact, shares are up 2% at 10:15 a.m. EST. That contrasts sharply with Facebook, which fell to a new low below $20 on Aug. 16, 2012, as a 90-day lockup expired. (Note, however, that the 271 million Facebook shares that became eligible for sale on that day represented a much larger proportion of the-then 421 million share float than is the case for Twitter.)

Personally, I'd recommend those insiders take some gains off the table. Last week, I wrote that "the overvaluation of Twitter shares was sufficiently extreme that I'm not at all convinced that today's [post-earnings] decline has eliminated it. ... It's far from obvious that the shares offer much value at $50." This week, New York University business professor Aswath Damodaran, the guru on company valuation, produced an updated estimate of Twitter's intrinsic value, which he puts at just $20.57. The blog post in which he describes how he arrived at that value ought to be required reading for anyone who owns or is considering owning the shares.

Meanwhile, one of the Twitter's largest investors, Rizvi Traverse Management is reportedly leading a funding round for Jawbone, which sells fitness wristbands and Bluetooth headsets, that would value the company at $3 billion. Last week, Wired highlighted 10 companies that Apple could acquire instead of buying back all that stock; most of the candidates had me shaking my head, but, of Jawbone, Wired wrote:

Of all the possible acquisitions Apple could make, San Francisco-based hardware designer Jawbone is the most obvious fit. ... With Nest off the table, Jawbone is the next-most-obvious option for Apple to leap forward in wearables and Internet of things-connected devices.

I agree. Like Nest, which Google recently acquired for $3.2 billion, and Apple, Jawbone clearly understands the power of design in selling premium-priced products.