NEW YORK–(BUSINESS WIRE)–Halper Sadeh LLC, an investor rights law firm, is investigating the sale of DoubleVerify Holdings, Inc. (NYSE: DV) to Nielsen Holdings for $13.60 per share in cash.Halper Sadeh encourages DoubleVerify shareholders to click here to learn more about their rights and options or contact Daniel Sadeh or Zachary Halper free of charge at (212) 763-0060 or sadeh@halpersadeh.com or zhalper@halpersadeh.com.The investigation concerns whether DoubleVerify and its board of director