The benchmark S&P 500 (SPX) closed Monday at 3,971, essentially unchanged on the session. I’m not surprised buyers took the day off, notes Jon Markman of Pivotal Point.

What is more shocking is the performance discrepancy between big- and small-capitalization stocks.

While the Dow Jones Industrials Average was climbing 0.3% Monday to a record, the Russell 2000 index, a key measure for smaller companies, was losing 2.8%. And the Nasdaq fell 0.3%. This narrowing of leadership is not a positive development and will bear watching the remainder of the week.

For now let’s give bulls the benefit of doubt as long as the S&P 500 remains above critical support at 3,877.

The reason for the market’s unease was in part reports of $30 billion in margin calls from an overleveraged family office and heavy prime broker losses at banks that provided credit.

Margin is a two-way street, amplifying positive returns and gutting negative returns. The Street is addicted to debt in a way most of us cannot imagine. I’ll never forget my surprise when I learned that a Wall Street firm that that had decided to invest $5 million in my hedge fund in 2003 told me that they borrowed the entire amount as a way to leverage their balance sheet. The Street treats debt like most of us treat water. It’s not part of the game; it is the game.

Consumer staples—i.e. soup, soda, and cigarette makers—fared best, along with drug makers and utilities fared best. Very defensive. The 10-year US Treasury yield rose to 1.72% from 1.66% Friday.

Breadth favored decliners by a 5-2 margin and there were 426 new highs vs 80 new lows. Topping the new high list were UnitedHealth (UNH), Home Depot (HD), Honeywell (HON), Union Pacific (UNP), 3M (MMM), Mondelez International (MDLZ), Marsh & McLennan (MMC), and Waste Management (WM). Grandparents’ stocks again.

Oil prices firmed even as the grounded giant container ship blocking the Suez Canal was refloated. West Texas Intermediate crude futures rose $0.56 to $61.53 per barrel.

Credit Suisse (CS) slumped 12% after saying it had suffered a loss it could not yet quantify, but which "could be highly significant and material" to first-quarter results after a US-based hedge fund default on the margin calls by the bank and other lenders last week. Nomura estimated its losses at $2 billion, prompting its stock to dive a record 16% in Tokyo trading.

Both banks were caught up in a liquidation of leveraged positions built with their credit by Archegos Capital Management, the family office of portfolio manager Bill Hwang. Its counterparties have been unwinding massive positions he had accumulated, WSJ reported. Goldman Sachs was down less than 1% after Bloomberg reported it was giving private assurances that it had not suffered material losses.

Boeing (BA) gained 2% to lead the Dow after announcing a revamped deal with key domestic customer Southwest Airlines (LUV) that will have Southwest buying 349 737 MAX planes over the next decade, 100 more than previously agreed.

Facebook (FB) gained nearly 3% after Deutsche Bank raised its target on the social media giant to $385 from $355, citing improving advertising spending and the company's growing ecommerce business as well as diminished worries about the effect of changes in Apple (AAPL) iOS operating system.

All in all, it was a fairly dull session as companies focus on closing a few final sales to improve their Q1 earnings. We’ll start to know how they did in less than two weeks; I’m looking for better than expected results as covid fears diminished businesses started to beat their plans and stimulus checks began to flow.

Learn more about Jon Markman at Pivotal Point.