Investing.com - "It's late but the party's still going."That's how Barclays (LON:BARC) described the long-running bull market in stocks in a note to its clients.The Wall Street firm says the stocks rally is entering a late stage but both the overall economy and corporate balance sheets remain healthy enough after nine years of expansion to keep it going. Barclays has a 2018 year-end price target for the S&P 500 of 2,900, which is just above its late January peak. The firm also listed what it sees as the most and least attractive sectors, with financials, health care and information technology in the overweight column and consumer discretionary and utilities in the underweight column.Like other firms, Barclays sounded a note of caution about the President's approach to trade, saying if it resulted in a trade war, the economic benefits of the tax cut package would lost.