Leading global financial holding company, The Goldman Sachs Group, Inc. GS has boosted optimism among investors by upgrading its year-end price target for the S&P 500 to 4,700 from the previously-stated 4,300 (per a YahooFinance article). This represents a rise of about 7% from the closing price on Aug 4. Going on, Goldman Sachs has also raised its S&P 500 price target to 4,900 for 2022 from the prior forecast of 4,600. An impressive S&P 500 companies earnings season and a dovish Fed have mostly been the tailwinds behind the revised forecast.In this regard, David Kostin, Goldman Sachs chief U.S. equity strategist, has noted that "We expect earnings growth will be the primary driver of U.S. equity returns in 2H 2021 and 2022, as it has been so far this year. Year-to-date, EPS [earnings per share] growth has accounted for all of the S&P 500's 17% price return. Looking forward, we forecast that modest equity risk premium ('ERP') compression will offset rising interest rates, resulting in an S&P 500 valuation multiple that remains roughly flat," per a YahooFinance article.The 10-year Treasury yield has been assumed to rise to 1.6% by 2021-end by Goldman Sachs in the baseline forecast, up from the present level of about 1.2%, as mentioned in a YahooFinance article. According to Kostin, the S&P 500 can rise even higher to 4,950 if rates remain low with strong growth expectations.Another assumption is that some version of President Joe Biden's tax reform plans will be passed before the end of the year and will have a nominal impact on corporate profits, according to the same article as stated above. However, the price targets are open to risks on uncertainty surrounding the coronavirus pandemic and the Federal Reserve’s stance on the fiscal and monetary policies.Going on, the latest development highlighting the bipartisan infrastructure bill of $550 billion, which the Senate introduced on Aug 1, in addition to the previously-approved funds of $450 billion for five years has also brought some optimism. Total spending may go up to $1.2 trillion if the plan is extended to eight years.Consumer confidence in the United States also seems impressive as it stays at its highest level since February 2020. The Conference Board's measure of consumer confidence index stands at 129.1 in July, comparing favorably with June’s reading of 128.9. Moreover, July’s reading beat the consensus estimate of the index declining to 123.9, per a Reuters’ poll. Strengthening optimism, coronavirus vaccines have been found to be effective against the delta variant.Moreover, the Fed’s continued support with easy monetary policies and fiscal stimulus support is strengthening hopes of rapid recovery from the coronavirus-led slump.ETFs to Ride the WaveInvestors who seek to capitalize on the strong trends should consider the following ETFs:SPDR S&P 500 ETF Trust SPYThis fund seeks to provide investment results that before expenses correspond generally to the price and the yield performance of the S&P 500 Index. Its AUM is $384.61 billion and the total expense ratio, 0.09%.iShares Core S&P 500 ETF IVVThe fund seeks to track the investment results of an index composed of large-capitalization U.S. equities. Its AUM is $296.84 billion and the total expense ratio, 0.03% (read: Most Interesting New ETFs of 2021).Vanguard S&P 500 ETF VOOThe fund seeks to track the performance of the S&P 500 Index. Its AUM is $246.04 billion and the total expense ratio, 0.03% (read: ETF Asset Report of July).SPDR Portfolio S&P 500 ETF SPLGThe fund seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of the S&P 500 Index. Its AUM is $11.64 billion and the total expense ratio, 0.03% (read: A Spread of Top S&P 500 ETFs to Tap Solid Q2 Earnings Growth).Invesco S&P 500 Top 50 ETF XLGThis fund follows the S&P 500 Top 50 Index, which measures the cap-weighted performance of 50 of the largest companies on the S&P 500 Index, reflecting the performance of the U.S. mega-cap stocks. It has been able to manage assets worth $2.04 billion. Expense ratio comes in at 0.20%. Infrastructure Stock Boom to Sweep America A massive push to rebuild the crumbling U.S. infrastructure will soon be underway. It’s bipartisan, urgent, and inevitable. Trillions will be spent. Fortunes will be made. The only question is “Will you get into the right stocks early when their growth potential is greatest?” Zacks has released a Special Report to help you do just that, and today it’s free. Discover 7 special companies that look to gain the most from construction and repair to roads, bridges, and buildings, plus cargo hauling and energy transformation on an almost unimaginable scale.Download FREE: How to Profit from Trillions on Spending for Infrastructure >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report The Goldman Sachs Group, Inc. (GS): Free Stock Analysis Report SPDR S&P 500 ETF (SPY): ETF Research Reports Vanguard S&P 500 ETF (VOO): ETF Research Reports iShares Core S&P 500 ETF (IVV): ETF Research Reports Invesco S&P 500 Top 50 ETF (XLG): ETF Research Reports SPDR Portfolio S&P 500 ETF (SPLG): ETF Research Reports To read this article on Zacks.com click here. 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