You don't have to buy Bitcoin (BTC 8.02%) or Ethereum (ETH 3.90%) tokens directly to gain some cryptocurrency exposure these days. Investors looking for a flexible stock exchange-listed play with little-to-no upfront costs may want to consider Grayscale Bitcoin Trust (GBTC 5.86%) or the smaller Grayscale Ethereum Trust (ETHE -0.91%) as a fresh portfolio addition.

There are some pros and cons for going with one of Grayscale's trusts, and we'll kick those tires soon enough. However, with the two investments now trading at rare discounts to their asset-backed portfolios it could be an opportunistic way to get some skin in the crypto game. 

Someone putting a coin with the Bitcoin logo into a golden piggy bank.

Image source: Getty Images.

Token of your affection 

Whether you see the merit of digital currency with an online ledger as a way to achieve diversification or you're just following in the footsteps of Elon Musk and Cathie Wood into crypto because you enjoy their market perspectives, you're not alone in your interest in cryptocurrency. Bitcoin is the token of choice for most investors, but Ethereum's blockchain technology is gaining momentum given its real-world functionality. The best solution -- if you've decided to go crypto -- may be to buy a little of both.

There is a growing number of ways to buy Bitcoin and Ethereum directly, but it's no easy feat through most traditional brokerages. The marketplace gets even leaner if you're trying to trade either currency in an IRA. It's here where Grayscale Bitcoin Trust and Grayscale Ethereum Trust step in as easily accessible exchange-listed choices. 

Grayscale Bitcoin Trust was launched in 2013 and went public two years later. With more than $36 billion in assets it owns nearly 4% of the world's Bitcoin supply. It has historically fetched a huge premium to its holdings, but a couple of weeks ago it began trading at a discount. Let's roll up our sleeves to size up the markdown opportunity.

It's a matter of trust

Grayscale Bitcoin Trust closed at $49.86 on Tuesday. A Bitcoin token was fetching $55,759.73 at that point. You need one more metric to work the math, and for that you would have to go to Grayscale's site to find that each share is currently backed by 0.00094623 of Bitcoin. Multiply the price of Bitcoin by that conversion rate and you arrive $52.76 per share, a 5.5% discount to Tuesday's market close.

Working the math on Grayscale Ethereum Trust -- with the crypto at $1,784.19 and a conversion rate of 0.01024320 -- is also kind for deal seekers. The product of $17.54 per share is a 4% discount to Tuesday's close of $18.28 for the trust.

Grayscale Bitcoin Trust is trading at the wider discount, and it's not the only difference. The reason why the conversion rate changes is that it contracts gradually to cover the pro-rated annual management fee. Grayscale Bitcoin Trust charges a stiff 2%, but Grayscale Ethereum Trust is even higher at 2.5%. 

The annual ransoms are high, but keep in mind that buying into crypto directly typically comes with a transaction fee of at least 1.5% of the purchase when buying and it can be slightly higher than that on the way out. Buying one of the Grayscale trusts through a commission-free broker helps ease some of the sting of the high annual fee.

If you are sure you're going to buy and hold for years then buying Bitcoin and Ethereum directly is the way to go. However, if you think you may have an itchy trigger finger or you prefer an exchange-listed vehicle that you can possibly put in your IRA either Grayscale trust makes sense in your case. 

I have positions in both trusts, and that along with a smaller direct Bitcoin position accounts for less than 4% of my portfolio. I want exposure to crypto, but I prefer stocks for the lion's share of my investing.

Which trust is right for you? Grayscale Bitcoin Trust gets the nod as the better buy given the lower annual fee and the wider discount, but Grayscale Ethereum Trust still offers a unique opportunity to capitalize on the country's second most popular cryptocurrency. We may never see the large double-digit premiums that the trusts were commanding just a few weeks ago, but the current discounts aren't likely to last forever.