Trio in Auburn Hills, Mich., join firm's employee unit.
But arbitrators said 30% of the fault lies with the 'negligent' claimants.
Singer Xenos Schechter Sosler, based in Coral Gables, is firm's sixth acquisition this year.
Debbie Smith joins employee unit at Buckhead office in Atlanta, Ga.
Frederick V. McDonald, Jr. allegedly failed to disclose risks and his own conflicts.
Robert Jackson Jr. is expected to join NYU Law School.
James Schwartz made 256 unauthorized trades in accounts of four clients.
Sheryl Garrett is this year's InvestmentNews Icon.
After Renee Altamirano declines to appear at a hearing, Finra bars her.
Frederick Holloway impersonated clients and altered documents, Finra says.
