Gap Inc., the biggest U.S. apparel-focused retailer, fell in early trading after comparable sales last month missed analysts’ estimates and the company provided some cautious commentary on the second half of the year.

Same-store sales — a key benchmark — dropped 4 percent in July, the San Francisco-based retailer said in a statement Monday. Analysts predicted a decline of 1 percent, according to Retail Metrics. The decline was broad-based, with sales by that measure missing analysts’ projections at all of the company’s major brands last month.

“Performance was uneven within the quarter, with challenging traffic in May and July,” Jack Calandra, senior vice president of investor relations, said on a recorded sales call. “As such, we’re maintaining a cautious view of the retail environment in the second half.”

The results stoked investor concerns that sales won’t get a needed boost from the back-to-school and holiday shopping seasons. CEO Art Peck, who took over the job last year, has said results would begin to improve at the Gap and Banana Republic brands this spring, but the recovery has been short-lived. While sales and traffic trends improved in June, they worsened in July, when many shoppers should be stocking up on clothes for the new school year.

Shares of Gap slipped as much as 7.1 percent to $23.79 in New York, the biggest intraday decline since May 10. The stock had gained 3.7 percent this year through the close on Monday.

“Gap has a conservative view of the second-half retail landscape reflecting volatile traffic,” Pamela Quintiliano, an analyst at SunTrust Robinson Humphrey, wrote in a note to clients Monday. “We expect fundamentals to remain challenged given the positive June comp proved to be an anomaly.”

On the positive side, second-quarter preliminary earnings ranged from 58 cents to 59 cents per share in the second quarter, excluding the impact of store closures and initiatives to streamline the business. That topped the 48 cents estimated by analysts. Gap is scheduled to report its full second-quarter results on Aug. 18.

Comparable sales plunged 14 percent at Banana Republic in July, more than the 4.6 percent decline expected by Retail Metrics. Sales by that measure were flat at Old Navy, missing estimates for a 1.1 percent increase. Gap’s sales slipped 4 percent, compared with estimates for a 1.5 percent decrease.

The results mark the 15th monthly same-store sales decline in the last 16 months, according to Ken Perkins, an analyst at Retail Metrics Inc.

“July proved to be difficult for retailers as hot weather, record Amazon Prime Day sales, the distractions of the beach and the Pokemon Go craze weighed on sales,” Perkins wrote in a note to clients after the results.