t() :: %Plaid.Investments.Holdings.Holding{
  account_id: String.t(),
  cost_basis: float() | nil,
  institution_price: float(),
  institution_price_as_of: String.t() | nil,
  institution_value: float(),
  iso_currency_code: String.t() | nil,
  quantity: float(),
  security_id: String.t(),
  unofficial_currency_code: String.t() | nil
}