1. Stellar Lumens (XLM)

Stellar began airdropping lumens to bitcoin holders in 2016. In July 2017, 1 XLM was worth about $0.02, and that airdrop was apportioned at the rate of almost 1,000 XLM to 1 BTC, or roughly $20. On January 4th 2018, lumens topped out at $0.85, 42.5 times what the value was originally.

2. Byteball (GBYTE)

Byteball made several airdrops starting on Christmas Day 2016, at the much less competitive rate of 1 GBYTE for every 16 BTC. 1 GBYTE was then about $19, which rose in mid-2017 to $945.33 and spiked again in January 2018 at over $1,000, more than 50 times its 2016 value.

3. TRON (TRX)

Sometimes airdrops will be made by cryptocurrency exchanges. One such in November 2017 dropped 500 TRX to active customers with 0.003 BTC or more in their account. TRX was then worth about $0.002, but on January 5th 2018 had risen to 0.21, a gain of over 1,000%.

4. eBitcoin (EBTC)

This combination of Bitcoin and ERC-20 tokens was airdropped to participants in September 2017 at the rate of 2,457.19916 eBTC each. In November, it opened at $0.20, and in January 2018 reached a peak of $1.96, giving holders a possible profit of $4,816.

5. Bitcoin Blue (BTCB)

Another ERC20 and Bitcoin combination, BTCB topped $2 in January 2018, from a standing start. Participants were each awarded 1,260 BTCB, rendering a yield of over $2,500.