The Federal Trade Commission recently issued a warning to members of the public to guard their finances as the number of digital-currency scams continues to rise.


Types of digital currencies include digital money, cryptocurrency and bitcoin.


“At first, scammers tried to get you to wire them money,” the FTC said in a recent online post. “Then, they demanded payment with gift cards.”


Here are three common scams to watch out for.


1. Blackmail scam


“Someone says they know about an alleged affair, or something else embarrassing to you, and demands payments with bitcoin or another cryptocurrency in exchange for keeping quiet,” the FTC post said. “These scammers might use threats, intimidation, and high-pressure tactics to get you to pay right away.”


The claims are a clear sign of a scam but also amount to attempted criminal extortion.


2. Online chain-referral schemes


These scams work like a chain letter in which someone promises that an individual will make money if he or she pays into the scheme.


“In a twist, these scammers say you have to use cryptocurrency to pay for the right to recruit other people into the chain…so that you’ll then be rewarded with more cryptocurrency,” the FTC post said. “Except you won’t. Instead, you’re guaranteed to lose money.”


3. Bogus investment opportunities


Scammers using this tactic will reach out to their intended victims with an invitation to “get in on the ground-floor” and entice them with returns that seem too good to be true.


“Someone might offer you investment and business opportunities that promise to make you big money, or give you financial freedom,” the FTC post said. “But remember, only a scammer will guarantee that you will make money — in dollars or in cryptocurrency.”


To report scamming attempts — successful or not — visit http://ftc.gov/complaint.