One of the drivers of corporate bond issuance over the past few years has been historically low interest rates, which began to change last year as the Federal Reserve tightened policy. But what had more of an impact was U.S. tax reform passed in late 2017, which included a provision allowing companies to repatriate foreign profits at a lower rate. This left many tech companies with little need to borrow.

Take Apple, for example. The company issued $30 billion of bonds across five deals in 2017, according to data compiled by Bloomberg. Of that, $29 billion went to the company's coffers for general corporate purposes.

Apple, like most other major tech issuers, was a bond market no-show in 2018. And the drought seems to be continuing across the sector. Alphabet Inc., Microsoft, Facebook Inc., and International Business Machines Corp. reported quarterly results with little to no indication they would be issuing bonds this year.

Technology companies may not even need to refinance existing debt, as the sector has more than enough cash to address upcoming bond maturities without issuing any new securities, according to Bloomberg Intelligence.

The lack of issuance has helped narrow high-grade bond spreads. For instance, Alphabet has more than $22 billion in free cash flow and hasn't recently issued any new debt, creating scarcity that's pushed its credit to trade at a premium to peers like AAA rated Microsoft, according to Schiffman.

That said, some tech companies may still need to sell bonds this year. There's $45 billion of investment-grade technology bonds maturing this year and several acquisitions that still need to be paid for. IBM may tap the debt market to pay off the $20 billion bridge loan it took to fund part of its Red Hat purchase last year. Broadcom is also in debt with $18 billion in outstanding loans from its purchase of CA Technologies.

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