It’s gut-check time for investors. Again. Greek elections on Sunday kicked off two potentially tumultuous weeks.

Last week, concern over a widening of the European debt crisis grew as Italy and Spain saw borrowing costs surge. There’s even been uneasy chatter about whether the potential exists for ‘‘another Lehman Brothers’’ — a reprise of the financial firm’s collapse at the heart of the 2008 financial crisis, with Greece playing the role of Lehman, perhaps joined later by Italy and Spain. The risk of Lehman II appeared to lessen on Sunday, when parties that support the terms of Greece’s bailout agreement won enough votes to form a coalition government. But average investors are still asking: What should I do to protect myself? The standard advice is to avoid doing anything rash. For long-term investors, reacting to headlines is rarely the right move.

Here are upcoming dates for investors to keep in mind, to gauge if progress is being made:

■  Monday and Tuesday: Leaders of the world’s 19 largest economies plus the European Union meet in Los Cabos, Mexico.

■ Tuesday and Wednesday: The Federal Reserve meets, with speculation swirling that it could extend Operation Twist to spur growth.

■ Thursday: Finance ministers of the 17 euro countries meet and are certain to discuss a pledge of $125 billion to rescue Spain’s banks.

■ Friday: Leaders of the four biggest economies among the euro countries — Germany, France, Italy, and Spain — meet in Rome.

■ June 28: Leaders of the European Union gather in Brussels.

Advice for investors

Keep fear and hunches out of any decisions.

Those in their 20s and 30s should ride this one out without tinkering with stock allocations. With decades to go before they need the money, odds are in their favor.

Those who intend to tap stock accounts in the next year or two, perhaps for college or retirement, may want to exercise more caution by reducing the percentage of stock funds in 401(k) accounts. Abandoning stocks would be a mistake, however.

Safe bets

One relatively safe bet is companies that make products and provide services that people buy no matter how bad the economy gets. Think food companies, drugstore chains, and makers of things like toothpaste. These companies are up a respectable 2.6 percent over the last three months. The S&P 500 is down 4.3 percent.

Or you could stick to companies that pay high dividends.

Telecommunications stocks have an average dividend yield of 4.8 percent. Utilities have an average dividend yield of 4.2 percent. For the whole S&P 500, it’s 2.4 percent.