Complex sentence: As development continued throughout the early 1960s, Bentele and Curtiss were accused of fraudulent activity, as investors and stocks soared however there was no real product on the market yet at the time.
Split into simpler sentences: As development continued throughout the early 1960s, Bentele and Curtiss were accused of fraudulent activity, as investors and stocks soared. However, there was no real product on the market yet at the time.