Amazon.com Inc. shares jumped about 4% Thursday afternoon after the company reported its largest quarterly profit total in history, disclosing earnings per share more than double what analysts expected. The e-commerce and cloud-computing company reported second-quarter net income of $2.5 billion, or $5.07 a share, up from earnings of 40 cents a share a year ago and the first time Amazon has reported more than $2 billion in quarterly profit. Amazon reported revenue of $52.9 billion, up from $37.96 billion a year ago but slightly lower than analyst estimates. Analysts on average were expecting earnings of $2.48 a share on sales of $53.37 billion. Amazon shares jumped more than 4% in immediate after-hours trading, following a 3% decline in the regular session to $1,808. The stock has gained 54.6% so far this year, as the S&P 500 index has increased 6.5%.