Qualcomm is one of the biggest players on chip market. Processors made by this company are considered as the best, and many devices currently available in shops has chipsets made by Qualcomm. However, finances of Qualcomm aren't in the best condition, because company's earnings are going down, and firm still has many cases in court with Apple, what consumes a lot of money from the budget.
That's why Broadcom decided to make an offer - they want to buy Qualcomm. For each share Broadcom wants to pay around 70$, so in overall whole transaction would give leaders of Qualcomm around 130 billion dollars. At this moment it looks that whole offer isn't satisfying for Qualcomm, but if trade will be accomplished it will be one of the biggest deals in the history of mobile market.