Shares in Googles parent company, Alphabet (Nasdaq: GOOG), are down nearly 7% in premarket trading at the time of this writing. The fall comes a day after Google announced its fourth-quarter 2024 earnings results. Heres what you need to know about those results and the likely reasons why GOOG stock is falling this morning.Google Q4 2024 results were a mixed bagGoogle saw both its revenue and earnings per share (EPS) increase in Q4 versus the quarter a year earlier. For the Q4 2024 quarter, Google posted nearly $96.5 billion in revenue12% growth from Q4 2023. However, in that previous Q4 2023 quarter, Googles revenue growth had been 13%, suggesting that growth is now slowing at the company, at least when comparing this quarter to the year-earlier quarter.Here are some of the most salient results from Googles Q4:Total revenue:$96.47 billionDiluted earnings per share (EPS):$2.15Google Cloud revenue:$11.96 billionYouTube ad revenue: $10.47 billionGoogle Services total revenue: $84.1 billionDespite growing at a slower rate in Q4 2024 than the same quarter a year earlier, Googles revenue is still trending in the right direction. Yet, as CNBC notes, analysts expected Google to bring in $96.56 billion for the quarter.Google also missed analyst expectations regarding its all-important Google Cloud revenue. For the quarter, Google posted cloud revenue of $11.96 billion, while analysts had expected to see around $12.19 billion. While Google Cloud revenue was up 30% year over year, Reuters notes that the sector had grown 35% in Q4 of 2023. This, too, shows that the growth of one of Googles primary revenue sources is slowing.Massive capital expenditure increase rattles investorsIn addition to missing analyst expectations on many fronts, the main thing that has rattled investors is Googles announcement that it will significantly expand capital expenditures in an effort to maintain any competitive lead it has in the artificial intelligence sector.Announcing the companys fourth-quarter 2024 results, Google CEO Sundar Pichai revealed that the company expects to invest approximately $75 billion in capital expenditures in 2025. As Reuters pointed out, most analysts had expected Google to grow capital expenditures to $58 billiona modest rise from the $52.5 billion it spent on capital expenditures in fiscal 2024.The $75 billion in expected capital expenditures for fiscal 2025 represents a massive capex growth of 29%. Google said that the majority of the capital expenditure will go into building data centers and servers. These resources are to a large part aimed at helping Google expand its AI capabilities.Yet many investors seem to have balked at this significant capex increase in the wake of DeepSeek. Last month, the Chinese AI startup claimed that it trained superior artificial intelligence models for less than $6 million, stunning both Wall Street investors and American artificial intelligence experts. American tech giants like Google have spent billions developing their artificial intelligence offerings.Many investors now are questioning whether Googles plans for additional expenditure are prudent considering what DeepSeek has achieved.On the companys financial call, Pichai conceded that the costs for using AI were coming down, but he argued that meant there would be more demand for AI in the future, and Google needs the infrastructure expansion to meet the demand.The cost of actually using (AI) is going to keep coming down, which will make more use cases feasible, he said. The opportunity space is as big as it comes, and thats why youre seeing us invest to meet that moment.GOOG is still up for 2025Despite GOOGs nearly 7% stock price fall in premarket trading this morning, the companys share price is still up slightly year-to-date. As of yesterdays close Googles shares were up nearly 7.8% since the beginning of January. The companys stock price has risen more than 44% in the past 12 months.