Ahead of Christmas, a few analysts were busy evaluating Twitter (TWTR) and Apple (AAPL 0.86%), and Amazon.com (AMZN -1.54%) squeezed in another acquisition. Here's what investors should know.

Twitter gets a big price target increase

Twitter was apparently the stock for analysts to get bullish on this week. One analyst from J.P. Morgan boosted his price target for the stock from $20 to $27, giving the stock an overweight rating. Another analyst from Summit Redstone initiated coverage of Twitter with a buy rating and a $26 price target.

A businessman using a smartphone in the back of a cab

Image source: Getty Images.

J.P. Morgan analyst Doug Anmuth said he expected Twitter's financial results to "strengthen over the next year," citing a forecast for continued momentum in double-digit daily active user growth, more product improvement, and a return to advertising revenue growth.

Summit Redstone analyst Jonathan Kees defended his buy rating for the stock by pointing to the company's "turnaround" in user growth and meaningful product improvements. Kees is also bullish on Twitter's data licensing business, which saw a 22% year-over-year increase in revenue in Twitter's third quarter. This compares to an 8% year-over-year decrease in advertising revenue during the same period.

Twitter stock jumped about 11% on Monday, following these two analyst notes.

China loves the iPhone X

Two analysts with bullish price targets for Apple stock were both intrigued by the same narrative this week: The iPhone X looks like a major hit in China.

RBC Capital analyst Amit Daryanani, who has a $190 price target on Apple stock, said there's robust demand for the iPhone X in China. Daryanani cited the firm's survey of Chinese consumers, which suggested about 62% of respondents who were interested in buying an iPhone wanted to buy the flagship iPhone X. Since the iPhone X is Apple's most expensive iPhone yet, this would be good for the iPhone's average selling price in a major smartphone market. On a similar note, Daryanani said customers want the highest storage version of the iPhone X, a trend that would push average selling prices even higher.

Meanwhile, Morgan Stanley analyst Katy Huberty said the iPhone X's popularity is driving a higher switching rate of those switching from Android to iPhone in China. She says the rate of those switching from Android to iPhone in the market is 9.2%, up from 6.7% in October. In addition, Huberty said the phone is causing iPhone owners in the market to upgrade at a faster rate.

Huberty has a $200 price target for Apple stock.

Amazon shows its smart home ambitions -- again

Amazon expanded its smart home products lineup this week when it acquired Blink, a company that makes battery-powered connected cameras and doorbells. Amazon confirmed the acquisition with The Verge.

A Blink camera mounted in a home

Blink camera. Image source: Blink.

The acquisitions follows Amazon's recent move to launch its own home security devices to complement its smart speaker ambitions. Amazon sells Amazon Key, Amazon Cloud Cam, and a smart lock, which together can enable remote access control.

Blink's specialty in smart cameras is its emphasis on "ultra-affordable" and "truly wire-free" products. Its standard camera starter set costs $99 and can hold a charge for two years on two AA batteries. A five-camera system can be purchased for just $349.

While Blink said it will continue to make and sell existing products under Amazon, it also plans to collaborate with the e-commerce giant. "It's Day 1 for us at Amazon, and we're looking forward to seeing what we can deliver to our customers together," Blink said.