S&P 500

On an ordinary day over the last month of trading, SPX has moved about 0.70%, making it about as volatile as most of the indices Kinzan tracks (their median is 0.75%).

Today's move is well inside its normal range: −0.2σ, an entirely ordinary session.

It sits around the middle of its 24-hour range of 7,658.49–7,682.79, measured on hourly closes.

Most of the move came in the New York session (13:00–22:00 UTC), which accounted for about 100% of the day's price action.

Over the last 60 sessions of daily returns, it has moved most closely with NDX (+0.90, a very strong relationship), and most inversely to VIX (−0.76).

Market read: The S&P 500 is flat, caught in a stalemate as New York selling offsets earlier stability.

What it is

The S&P 500 tracks roughly 500 of the largest companies listed in the United States, weighted by the market value of their freely traded shares. Constituents are chosen by a committee at S&P Dow Jones Indices, which requires profitability and adequate liquidity rather than applying a purely mechanical cut-off. The index covers most of the total value of the US stock market and is the benchmark against which most US equity fund managers are judged, so trillions of dollars in index funds track it directly.

What drives it

Over long horizons, corporate earnings are the anchor: the index rises broadly as profits grow. Around that trend, valuations expand and contract with interest rates and risk appetite. Lower Treasury yields and an easier Federal Reserve have generally supported higher valuation multiples, while inflation surprises and tighter policy have tended to compress them. Quarterly earnings seasons, especially results from the largest constituents, can move the whole index because a handful of megacap technology and communication companies now carry a large share of its weight. Macroeconomic releases — payrolls, CPI, retail sales, purchasing managers’ surveys — shape expectations for both growth and policy.

How it trades through the day

The cash index is calculated only during the regular New York Stock Exchange session, 09:30 to 16:00 New York time, which falls within the site’s New York block (13:00–22:00 UTC). Outside those hours, S&P 500 futures (the E-mini contract on CME) trade nearly around the clock, so the index’s direction is often visible in the Asia block (22:00–07:00 UTC) and the London block (07:00–13:00 UTC) before the cash open. Volume is typically highest in the first and last hour of the cash session, and the closing auction carries heavy index-fund flow.

What it tends to move with

The S&P 500 tends to move with the Nasdaq 100 and the Dow Jones, with the Nasdaq usually showing larger swings. It has historically moved inversely to the VIX, which is derived from options on the S&P 500 itself. It tends to rise with risk-sensitive currencies such as AUD/USD, and its link with Treasury yields flips between positive and negative depending on whether markets are focused on growth or inflation.