Shares of Sears Holding Corp. soared Monday to a two-month high, after the troubled department store chain’s biggest shareholders stepped in to boost their stakes just as concerns over the retailer’s future reached a fever pitch.

In a filing with the Securities and Exchange Commission late Friday, Chief Executive Edward Lampert disclosed that he spent about $4.2 million to buy a total of 507,936 shares from Wednesday through Friday, at a weighted average price of $8.21. That increased his stake to 31.84 million shares, or 29.8% of the shares outstanding.

Edward Lampert’s share purchases of Sears last week Date Shares bought Average price paid (intraday range) March 22 327,879 $7.829 ($7.85-$8.33) March 23 178,109 $8.072 ($7.85-$8.49) March 24 19,948 $8.3934 ($8.07-$8.53) S-4 filing with the Securities and Exchange Commission

On Wednesday, Sears’ stock US:SHLD had plunged 12% after warning in its annual report that it had “substantial doubt” that it would be able to “continue as a going concern” if its turnaround plan failed. The company said in the filing, however, that it believed the actions it has been taking would likely mitigate that substantial doubt. Lampert’s share purchases may help reinforce that belief among investors.

Don’t miss: Why Sears, but not its auditor, gave a going-concern warning.

See also: Sears is closing stores, but they may not be a done deal for bargains.

The same day of the “going concern” warning, Sears’ second largest shareholder, Fairholme Capital Management, disclosed that it paid about $5 million to buy 613,900 shares at a weighted average of $8.17 that week, with the bulk of those purchases coming as the stock dipped on Wednesday.

That raised Fairholme’s stock in Sears to 28.56 million shares, or 26.7% of the shares outstanding.

Fairholme Capital Management share purchases of Sears last week Date Shares bought Average price paid (intraday range) March 20 6,700 $8.99 ($8.92-$9.19) March 21 150,000 $9.00 ($8.84-$9.14) March 22 376,200 $7.87 ($7.60-$8.33) March 22 40,000 $7.96 ($7.60-$8.33) March 22 41,000 $8 ($7.60-$8.33) S-4 filing with the Securities and Exchange Commission

In total, Lampert and Fairholme paid a combined $6.2 million to buy 785,079 shares on Wednesday as the stock plunged.