Share prices in the nation’s top insurance companies have grown since President Obama’s nationally televised speech on healthcare reform. During the address, Obama criticized insurers but also said he wants to keep them in business. Obama also refused to insist on a government-funded public option and backed a proposal that would force Americans to carry health insurance, giving insurers millions of potential new customers. On Thursday, shares in major insurance companies, including UnitedHealth, WellPoint and CIGNA, rose between one to four percent. The investment research firm Sanford Bernstein says it’s now “even more confident after the Obama speech that the legislative outcomes will be moderate with no threat of a Medicare-like public plan.”