An article in the Wall Street Journal notes that “investors tend to view [preferred stock] more like bonds than like [common] stock.”

a. In what sense is preferred stock more like bonds than like common stock?

b. Many companies issue preferred stock with a provision that allows the company to buy back the preferred stock at its original price after five years. The article notes that this provision “can produce unexpected losses for investors.” When would companies be likely to buy back their preferred shares?
Why might these buybacks cause losses to investors?