Daniel Tacktill: Oppenheimer Advisor Receives $1.5mm Complaint

Melville, New York financial advisor Daniel Tacktill (CRD# 4624409) recently received an investor complaint alleging that his conduct resulted in damages exceeding $1 million. Financial Industry Regulatory Authority records show that he is registered as a broker and an investment advisor with Oppenheimer & Company.

Mr. Tacktill’s BrokerCheck report discloses one investor complaint. Filed in July 2026, it alleges that as a representative of Oppenheimer, he breached his fiduciary duty, committed fraud, engaged in unjust enrichment, breached contract, failed to recognize the client’s power of attorney, converted funds, was negligent in his supervisory duties, and misappropriated or failed to account for trust assets. The pending complaint alleges damages of $1.5 million.

In comments included with the complaint’s disclosure, Mr. Tacktill defended himself against the allegations. “I at all times conducted myself in an appropriate and professional manner,” he wrote. “I deny all allegations of wrongdoing, and intend to vigorously defend myself against the false, unwarranted and unsubstantiated allegations.”

Investors should be aware that the misappropriation of client funds may be considered a violation of FINRA Rule 2150, under which no FINRA-associated person “shall make improper use of a customer’s securities or funds.” It may also be considered a violation of FINRA Rule 2010, which stipulates that brokers like Mr. Tacktill must “observe high standards of commercial honor and just and equitable principles of trade” in the conduct of their business. Brokers who violate these rules may be held liable for damages.

According to the Financial Industry Regulatory Authority, Daniel Tacktill holds 21 years of securities industry experience. Based in Melville, New York, he has been registered as a broker and an investment advisor with Oppenheimer since 2006 and 2007, respectively. His past registrations include Sandgrain Securities and UBS Financial Services. His credentials include the passage of four securities industry qualifying exams: the Securities Industry Essentials Examination, or SIE; the General Securities Representative Examination, or Series 7; the Uniform Combined State Law Examination, or Series 66; and the Uniform Investment Adviser Law Examination, or Series 65. He holds 34 state licenses. (Information current as of August 25, 2026.)

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