People queuing outside Shake Shack in London. Latest Covid-19 lockdown slams UK business owners.

Check out the companies making headlines in midday trading.

Shake Shack — The fast food chain's stock jumped 7.8% after the Wall Street Journal reported that activist investor Engaged Capital is planning a proxy fight for three board seats at the company. Engaged Capital bought a 6.6% stake in Shake Shack, including swaps. The stock has rebounded more than 60% this year.