During this shortened trading week, May ended strong, with the S&P 500 setting another record high by Thursday's close. The bulk of earnings have now been released, and though earnings season is winding down, there were some Canadian financial institutions (BMO, BNS) that announced strong, estimate-beating results, while some retailers (GES, ANF, DSW) posted mixed or negative results. May's M&A activity continued to be strong this week, with Tyson Foods (TSN) outbidding Pilgrim's Pride for Hillshire Brands (HSH), Snap-on Incorporated buying Pro-Cut International, and Apple (AAPL) announcing that it has purchased Beats Music and Beats Electronics, adding Dr. Dre and Jimmy Iovine to the Apple team. In macro news, April's Personal Income came in with a 0.3% growth, matching estimates, while April Spending was down 0.1%, below the estimates of a 0.2% gain. In employment news, there was a positive Initial Jobless Claims report, with claims coming in at 300,000, below the expectations of 318,000. One negative release that investors all but ignored during Thursday's trading was the revised U.S. GDP number for Q1, which came in down 1%, versus the estimate of a 0.5% decrease. Amid the strong trading week, 10-Year Treasury yields fell to 2.45 to close out Thursday, after starting out the week at 2.52. Below, we look at all of Moody's municipal bond upgrades and downgrades from the past week.

Upgrades

• Radnor Township School District, PA: Moody's upgraded this school district's general obligation rating to Aa1 from Aa2. The upgrade to Aa1 reflects the sustained strengthening of the district's financial position over the past five years, resulting in a healthy financial position and strong cash levels. The rating also incorporates the district's moderately sized tax base with above average socioeconomic characteristics, the stabilizing presence of Villanova University (rated A1 stable), and average debt levels.
• Greater New Orleans Expressway Commission, LA: Moody's upgraded this commission's revenue bonds to A3 from Baa1. The upgrade is based on stabilized traffic and toll revenue, improved Vehicle License Tax (VLT) receipts and a strong liquidity position, as well as enhanced support for the Series 2003 bonds from supplemental reserve insurance policy from Assured Guaranty Municipal Corp (A2, stable). These factors are balanced by the single-asset nature of the causeway, weak local and national economic conditions.
• Metropolitan Atlanta Rapid Transit Authority, GA: Moody's upgraded this transit authority to Aa3 from A1. The upgrade to Aa3 reflects restructuring of a formerly outsized variable rate debt and swap portfolio; growth in pledged revenues after multiple years of contraction; improvement in MARTA's cash position; a relatively low additional bonds test mitigated by sufficient debt service coverage; and easing pressure on the system's operations evidenced by its $9 million fiscal 2013 budgetary surplus.

Downgrades

• Cook County School District#144 (Prairie-Hills), IL: Moody's downgraded this school district to Baa1 from A1. The Baa1 rating reflects the district's declining tax base with a weak demographic profile, substantial declines in Operating Fund reserves since 2010 and a reliance on pressured state aid revenues, and an above average debt burden that continues to grow as the district uses refunding techniques to extend its overall amortization schedule for near term tax rate relief.
• Wayne Memorial Hospital, NC: Moody's downgraded this hospital to Baa1 from A3. The downgrade to Baa1 reflects recent weak operating performance and low revenue growth, and our expectation that operations will remain suppressed over the near term. The stable outlook at the lower rating level reflects Wayne's solid market position as the only acute care hospital in its primary service area and a strong balance sheet which affords the organization time to implement performance improvement initiatives.
• La Habra City School District, CA: Moody's downgraded this school district to Aa3 from Aa2. The downgrade of the district reflects the ongoing operating deficits, declines in the fund balance levels projected to be 8.6% of revenues in fiscal 2014 and the projected narrowing of liquidity to 1.8% of revenues in fiscal 2014. The rating also incorporates the district's sizeable tax base which has grown 2.7% since 2012 as well as a debt and pension burden that are low relative to similarly rated California school districts.
• Maricopa County School District 90, AZ: Moody's downgraded this school district to Baa2 from Baa1. The downgrade to Baa2 reflects significant declines in general fund balance and available cash since leaving state receivership driven by multiple years of structural imbalance. The rating also considers the moderately sized tax base with large concentration among top taxpayers and a low debt burden.
• Heritage Valley Health System, PA: Moody's downgraded this healthy system to A2 from A1. he downgrade to A2 follows thin financial performance through six months of FY 2014, which, while trending better than FY 2013, is soft relative to the 2014 budget and A1 rated medians. The downgrade also reflects Heritage's multi-year departure from its historic operating profile generating variable financial performance that has been below the A1 medians since 2011.