The stock market has had a reasonably positive tone over the past week, and investors seemed ready to take a break in Friday's quiet session. Major indexes traded on either side of unchanged during the day, but they never strayed too far from where they had finished on Thursday. By the close, the Dow Jones Industrial Average (^DJI -0.28%) and S&P 500 (^GSPC 0.25%) gave up a bit of ground, while the Nasdaq Composite (^IXIC 0.81%) inched higher.

Index

Daily Percentage Change

Daily Point Change

Dow

(0.15%)

(46)

S&P 500

(0.08%)

(3)

Nasdaq

+0.12%

+14

Data source: Yahoo! Finance.

A couple of stocks made substantial moves to the upside. Kura Sushi (KRUS 2.68%) and iRhythm Technologies (IRTC 4.63%) aren't household names for most investors, but they're rapidly getting the attention of the broader investment community with their recent performance. Let's look to see why both stocks were up more than 20% on Friday.

Kura delivers

Shares of Kura Sushi jumped 34% on Friday. Investors liked the restaurant chain's latest financial results and hope to see more of the same as the year progresses.

Kura's fiscal third-quarter report for the period ending May 31 was unexpectedly strong. Revenue more than doubled to $38 million during the period, with comparable restaurant sales soaring 65% year over year. Although operating income inched lower during the period, Kura surprisingly turned around a sizable loss in the year-ago quarter and produced adjusted earnings of $0.05 per share.

CEO Hajime Uba attributed the results to a number of factors. Kura has enjoyed  significant growth throughout its current fiscal year, but instrumental to its success has been its employees' efforts to minimize the impact of inflation on operations. Also, Kura has entered new markets, most recently in the Boston suburb of Watertown, and it expects to open at least eight new restaurant locations before the end of the fiscal year.

After a couple of years of having to get prepared food delivered, customers are ready to eat out again. Kura is benefiting from that trend, and its momentum could easily continue for the remainder of 2022 and beyond.

iRhythm looks to get paid

Elsewhere, iRhythm Technologies enjoyed a 23% rise in its share price. The digital healthcare specialist commented on the proposed 2023 Medicare fee schedule for its Zio XT heart monitoring service, and stock analysts responded favorably.

iRhythm's  comments were relatively arcane, making reference to various codings and reimbursement amounts for Medicare patients. The company expects that it could receive just over $200 for national payment rates under the program. However, various modifiers for certain geographical areas could lead to a higher range of up to nearly $300 in some cases.

Those numbers were more favorable than some had expected, and analysts at Truist weighed in with positive comments after the announcement. Truist had expected a lower proposed Medicare reimbursement rate, and it now believes that the announcement could serve as a catalyst to send the stock higher. Truist already had a buy rating on iRhythm, with a price target of $165 per share. Even with today's big gain, that target still leaves around 15% to 20% of potential near-term upside left for investors.

iRhythm got a big boost back in November when Medicare announced its 2022 fee schedule, so it's not surprising to see a similar reception this time around. With so many patients potentially benefiting from the Zio XT product, securing favorable Medicare funding is an important element of iRhythm's long-term business strategy to become profitable.