What is the relationship between Maftir Jonah and the ’Parnasah Segulah’ - to the Oleh? Is there a source or a hint for this or is it just a minhag that developed?
Rabbi Gavriel Zinner, in his book Nitei Gavriel on the laws of Yom Kippur (chapter 62, paragraph 16) brings sources citing the Rebbe of Lubavitch, the MaHaritz, that the Aliyah of Maftir Yonah on Yom Kippur "gives the power of Teshuva (repentance) and also is a segulah for wealth" (HaMelech Bimsibo, Vol. I, p. 73). He also cites the brother-in-law of the previous Rebbe of Lubavitch who asked the Rebbe why people strive to attain this Aliyah. He answered: "It has many segulot".