Anna Wintour's name has been synonymous with what is fashionable in the world's leading capitals for years. The mere fact that even a fashion novice like me knows that speaks volumes about the clout the former editor-in-chief of Vogue, and now artistic director for Condé Nast, has wielded for close on three decades. For many retailers, following her seasonal whims for the most part proved a winning ticket. And as long as editors such as Wintour - who served as inspiration for the lead character in The Devil Wears Prada - held centre court, clothing retailers and their buyers had a clear route to understanding what the market desired.No more. Fashion fundis abound and they live in the realms of Instagram, Twitter, Facebook, YouTube and Pinterest, to name a few.In years gone by, the latest trend was largely dependent on what the most popular fashion magazine punted when it hit the stands. I imagine it made for a more manageable purchasing template for retailers.But in this new world, trends drop at any given moment, as volatile - if not more so - than the rand.story_article_left1A dress worn by Rihanna, a torn T-shirt by Kanye West or what American blogger Chiara Ferragni has to say from her base in Los Angeles, determines that day's fad.Keeping abreast of these developments is a 24-hour operation - and for a fashion buyer at any one of South Africa's leading players, a migraine.One can only picture the rising insomnia levels.Mr Price finds itself in the middle of this storm, especially as its clothes cater for a demographic most exposed to these fast-evolving changes.I'm not intentionally writing a series of columns about disruption. However, the challenges facing Mr Price are similar to those posed by the imminent arrival of an offering from Discovery in the banking sector.The most recent trading updates from the retailer have surprised markets with the quantum of its struggles.Being a primarily cash-based retailer, Mr Price was for the longest time buffered from the credit cycles of the economy. With borrowing costs rising over the past two years, it was expected to hold up much better than rivals Truworths and The Foschini Group.But over the past year the company's stock has performed worse than that of its rivals. From a record high in April last year, the one-time retail darling's share price has slumped almost 50%.This is not simply a case of a company in a weak economy with shrinking disposable income levels. It made a fashion misstep - and it won't be the last time a fashion retailer as big as Mr Price stumbles.story_article_right2It's a heightened risk with any fashion player in this day and age. In a couple of quarters, if not the next, Mr Price could possibly meet the season's fashion demands and reap immediate rewards in sales growth.The quarter after, the buyers could miss the boat - and this applies across the board, especially to those retailers that pride themselves on being at the cutting edge of fashion.And therein lies the difference with the clothing offering of Woolworths.Its clothing - with the exception of its children's range - appears to be a carefully calibrated few steps behind the pulse of current fashion trends. It's a safe bet - we all need white shirts and chinos, with the right cut.The real jewel is Woolworths' food business.The fashion world is shaking the foundations of Mr Price - much as it shook those of Edcon, the owner of Edgars. It needs answers - fast-evolving ones.E-mail derbyr@sundaytimes.co.za or find him on Twitter @ronderby..