Protagonist, Schlumberger fall; Invesco, Thermo Fisher rise

NEW YORK (AP) — Stocks that traded heavily or had substantial price changes Friday:

Invesco Ltd., up $1.36 to $26.25.

The investment management company is reportedly in talks on a potential deal with State Street's asset-management business.

Thermo Fisher Scientific Inc., up $36.36 to $596.80.

The maker of scientific instruments and laboratory supplies gave investors an encouraging business update.

Lincoln National Corp., up 96 cents to $67.54.

The insurance and retirement business announced a reinsurance deal that will generate about $1.2 billion of capital.

Diamondback Energy Inc., up $2.55 to $82.62.

The oil and gas company announced a $2 billion stock buyback plan.

Protagonist Therapeutics Inc., down $28.60 to $17.53.

The biotechnology company's development program for drug candidate rusfertide was put on hold by the Food and Drug Administration.

Schlumberger NV, down 55 cents to $28.31.

Slumping oil prices weighed down the oilfield service company's stock, along with other energy companies.

Enbridge Inc., down 41 cents to $39.65.

Minnesota regulators ordered the oil and gas pipeline to pay more than $3 million for allegedly violating a state environmental law.

Norwegian Cruise Line Holdings Ltd., up 53 cents to $25.59.

The cruise line operator gave investors an encouraging update on bookings for its Oceania Cruises business.