"For initial listing on the NASDAQ SmallCap Market, the preferred stock must have three market makers and meet the minimum $4.00 bid price requirement. for continued inclusion, the preferred stock must have tewo market makers and meet the minimum $1.00 bid price requirement.
{Marketplace Rules 4310(c)(01) - market makers, and 4310(c)(04) -bid}. See Listing Requirements and Fees (PDF)"