After strong gains throughout most of last week, investors took a more cautious stance on Monday, pushing major averages down slightly. E-commerce Stocks epitomized recent trading activity, losing ground during the session after substantial gains in the previous few sessions.

Shopify (SHOP) led the e-commerce retreat, posting a double-digit percentage loss. Chewy (CHWY), Wayfair (W) and Etsy (ETSY) also lost ground.

Elsewhere in the market, M&A activity was a major contributor to the session. Anaplan (NYSE: PLAN) and Alleghany (NYSE: O) both jumped after separate deals to be acquired. Meanwhile, Nielsen (NLSN) fell after rejecting a takeover offer.

In other news, ImmunoGen (IMGN) suffered a sell-off after revealing clinical trial data for a potential ovarian cancer drug.

Focus on the sector

E-commerce stocks posted notable losses on Monday, reversing some of the gains recorded in previous sessions. Investors took some of their profits after the struggling sector helped lead last week’s overall rebound on Wall Street.

Shopify (SHOP) was at the forefront of trade of the day in the industry. The stock fell 12% after rising nearly 30% in a four-session rally last week.

Chewy (CHWY) was another notable loser in the group, falling almost 7%. Wayfair (W) fell 5%, while Etsy (ETSY) fell around 4%.

Outstanding Winner

A takeover deal triggered the purchase of Anaplan (PLAN). Shares of the business planning software maker soared 28% on news of the $10.7 billion deal.

The stock jumped after private equity firm Thoma Bravo reached an agreement to buy PLAN for $66 a share in cash. The company will continue to operate under CEO Frank Calderoni.

PLAN posted a gain of $14.01, ending Monday at $64.60. The advance added to gains recorded in previous days, with the stock hitting its highest level since November.

Outstanding Loser

Nielsen (NLSN) fell nearly 7% after rejecting a takeover bid from a private equity consortium.

The company, which tracks television and internet viewership, rejected a $9 billion offer, valued at $25.40 a share. NLSN said the offer significantly undervalued its prospects.

NLSN plunged in early trading as investors reacted to the news, with the stock falling more than 16% at its session low. Shares rallied through the morning and early afternoon, although they remained $1.68 lower at the close. The stock ended the day at $22.76.

Overall, stocks have surged over the past few days as talk of a potential takeover swirled around Wall Street. The stock closed at $16.69 on March 7. Even with Monday’s drop, the stock is still up 36% since then.

Notable new peak

Warren Buffett’s love propelled Alleghany (Y) to a new high, as a buyout deal from Berkshire Hathaway (BRK.A) (BRK.B) fueled a rally in the insurance company’s shares. The stock soared nearly 25%.

Under the terms of the agreement, Berkshire Hathaway will pay $848.02 per share in cash to acquire Y, resulting in a total net worth for the transaction of $11.6 billion. This represents a 29% premium to the average share price over the past 30 days.

Y ended the session at $844.60, a rally of $168.57 on the day. With the advance, the stock set a new 52-week intraday high of $853.20.

Entering the deal, Y has largely moved sideways for most of 2021 and the first part of 2022, although it slipped to a 52-week low of $585.10 earlier this month.

New notable low

ImmunoGen (IMGN) fell 18% following the release of data for a drug in development for ovarian cancer. The stock, which also suffered a downgrade from RBC Capital Markets, hit a 52-week low with the decline.

IMGN has released final clinical trial data for its product mirvetuximab in platinum-resistant ovarian cancer. The company said the trial met its primary endpoint, with a confirmed objective response rate of 32.4%.

However, RBC downgraded its rating on IMGN to Sector Perform from Outperform. Analyst Kennen MacKay warned that the trial’s median progression-free survival results raise “questions of ‘clinical significance'” and suggest “substantial risk” to the product.

IMGN pulled back 96 cents to close the session at $4.30. During the day, the stock hit a 52-week intraday low of $3.83.

The slide took stocks below a recent trading range. IMGN had traded above $10 at the start of last February. The stock has fallen about 50% over the past year.

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