An optimistic start to the week turned south pretty quick following a sprinkling of non-major economic data. Shortly after Alibaba’s IPO on Friday, the company’s debut was officially declared the largest IPO ever: the $25 billion flotation is completely unmatched after the e-commerce giant’s share price rose 38% on Friday. Today however, profit takers are afoot as the stock declined over 4.0%. Apple's (AAPL) first-weekend sales of the iPhone 6 family of smartphones topped 10 million units, roughly in line with analyst expectations but not enough to thoroughly impress so the tech sector is tumbling today. On the note of China, investors are particularly weary today since tonight HSBC will release its flash reading for the county’s manufacturing PMI. The manufacturing sector in China is already teetering on the level of no expansion (near 50.0 at 50.2 in August), so a reading in the 40’s would be a substantial blow to investor optimism. The Dow Jones Industrial Average is down roughly 0.4% while the S&P 500 and the NASDAQ are trading substantially lower. There was no decisive market mover of the day, but some economic data may have contributed to a significant decline in sentiment.

Firstly, we learned from the Chicago Fed that there has been a slowdown in production nationwide. The Chicago Fed National Activity Index (CFNAI) reading fell to -0.21; lower than the downwardly revised reading of 0.26 in July. Consensus estimated that the production level would only fall 4 basis points to 0.35 from the original July reading of 0.39. The sales/orders/inventories component was the best category in the CFNAI as it grew to 0.08 in August from 0.04 in July. However, with employment, manufacturing, and consumption down, we are looking at potentially lower consumer confidence and employment figures to be released later on this week.

Though the CFNAI missed expectations, the biggest disappointment “du jour” was out of the housing sector. Existing home sales declined 1.8% in August to a lower-than-expected annual rate of 5.05 million units. This was far shy of the economic consensus estimate of 5.18 million units. Year-on-year, sales are down 5.3%, which is quite a bit more steep than the -4.5% year-over-year in the prior month. However, limited supply has been a major contributor to the decline in sales, with supply on the market falling by 40,000 homes to 2.31 million. Supply relative to sales, at 5.5 months, held unchanged reflecting the August's sales dip. Home prices have also been flat for the past half year, down 0.8% in August to a median home value of $219,800. On a regional basis, August’s weakness was primarily in the West, where existing home sales were down 6.0% over last month. The South was also down by 4.2%, but the North and Midwest were positive at 4.7% and 2.5% respectively. A lack of first-time buyers and a weak jobs market continue to contribute to the lack in home sales. A hidden factor holding back sales is a lack of distressed sales on the market, at a recovery low of 8% in August's sales data. Wednesday, we will receive a read on the new home sales – which is a far bigger gauge of overall economic health.