The combined firm will be based in Akron, Ohio, and operate under the Sequoia brand.
It will offer financial planning, wealth management, asset management and business consulting services to clients and their families.
The merger is expected to close in the second quarter and financial terms were not disclosed.
Wealthstone principals Jim Wyland, Norm Cook, Brian Stertzer, and Jack Zhang will become shareholders of Sequoia.
Upon completion of the merger, Sequoia Financial Group will employ approximately 110 people and have more than $7bn (£5.02bn, €5.78bn) in assets.
Sun Life Financial
The insurance firm has agreed to acquire Pinnacle Care International, a US medical intelligence and health-care navigation provider, for $85m.
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