Ask any of my subscribers, and they’ll tell you, I love earnings season, really and truly.

You only have to look at yesterday’s  market action to understand why. The Dow finished  up a shade under 200 points on positive earnings news.

But this goes so much further than one good day for the indices.

My love affair with earnings season stems from the fact that over the past 30 years, I have found that some 90% of my market-trouncing profits were made during the critical weeks of earnings season.

I’m talking double-digit profits from safe, reliable blue chip stocks like these:

• Apple (NASDAQ:AAPL) announced 73% sales growth, doubled their earnings growth and posted a 30% earnings surprise on January 24–pushing the stock 24% higher.

• Novo Nordisk (NYSE:NVO) posted 12% sales growth, 19% earnings growth and a 16% earnings surprise on February 2. This sent the stock on a profit run of 25% and climbing.

• Teradata (NYSE:TDC) reported that it had its best quarter ever in terms of sales and earnings growth on February 9. Sales advanced 23%, earnings jumped 25% and the company posted a 6% earnings surprise.

But let’s be clear, these double-digit swings can work in the opposite direction, too. That’s because earnings season is Judgment Day for any company.

Case in point is JPMorgan (NYSE:JPM), which announced lackluster first-quarter results last Friday. Even though the company increased its earnings per share by 2% due to lower share count, the company’s net income still slipped 4%. Investors did not react well to this, so shares gapped down 4% after its earnings announcement.

Yes, in today’s market, even stocks that have been on a run or stocks considered to be “old reliables” aren’t safe havens anymore. If the quarterly report isn’t good, Wall Street will sentence a company’s stock to a 5%, 10%, even 20% drop in price. (Ouch!) But if a company’s earnings are strong, you can bank on instant and dramatic profits.

That’s why for the next two weeks we’re going to watch every report, and I’m going to be there to help you navigate to the biggest winners and away from the biggest losers.